DWL Tells You The Common Coating Types of Color Coated Steel
2020年2月21日
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Common coating types color coated steel
A. polyester (PE, Polyester)
PE coating has good adhesion to materials, color coated steel plate is easy to process and form, cheap and many products, and the choice of color and gloss is large. Polyester coatings are not ideal for UV resistance and powdering resistance of coatings. Therefore, the use of PE coatings still needs to be limited. It is generally used in areas where air pollution is not serious or products that require multiple molding processes. Applicable industry: Ordinary industrial plants and warehouse logistics warehouses do not corrode the color-coated plates themselves. The requirements for corrosion resistance and anti-aging of color plates are not high. More consideration is given to the practicality and cost-effectiveness of plant construction.
B. Silicon Modified Polyester (SMP, Silicone Mobified Polyester)
Since the polyester contains an active group -OH/-COOH, it is easily reacted with other macromolecular substances. In order to improve the sunlight resistance and pulverization of PE, the chromic retention and heat resistance of the Silicone resin are denatured. , The denaturation ratio of PE and PE can be between 5% and 50%. SMP provides better durability of the steel color-coated plates, and its corrosion protection period can be as long as 10-12 years. Of course, its price is also higher than PE. However, because the adhesion and processing formability of the Silicone resin is not ideal, the SMP color-coated plates is not suitable for applications requiring multiple molding processes, and is mostly used for building roofs and exterior walls.
C. high weather resistant polyester (HDP, High durable Polyster)
For the shortcomings of PE and SMP, HYDRO (now acquired by BASF) and BECKER of Sweden developed a 60-80% weatherable HDP polyester coating that can achieve PVDF coating in early 2000, and is superior to ordinary silicon modification. The polyester coating has an outdoor weather resistance of 15 years. The high weathering polyester resin is synthesized by using a monomer containing a cyclohexane structure to achieve flexibility, weather resistance and cost balance of the resin, and the aromatic-free polyol and polybasic acid are used to reduce the absorption of UV light by the resin. To achieve high weather resistance of the coating. UV coatings and hindered amines (HALS) are added to the coating formulation to improve the weather resistance of the film. High weathering polyester coil coatings have been recognized in the market abroad, and the cost performance of this coating is very prominent. Applicable industry: Metallurgical and power industry non-ferrous metal smelters (copper, zinc, aluminum, lead, etc.) are the most challenging years of use of color plates. Steel plants, power plants, etc. will also produce corrosive media, and have high corrosion resistance requirements for color plates.
D. PVC plastic sol (PVC Plastisol)
PVC resin has good water resistance and chemical resistance, and is generally coated with a high solid content, and its coating thickness is between l00 and 300 μm. It can provide smooth PVC coating or light embossing treatment as embossing coating; because PVC coating is thermoplastic resin, it has high film thickness and can provide good protection of steel plate. However, PVC has weak heat resistance. It was used more in Europe in the early days, and it is currently used less and less because of its relatively poor environmental protection.
E. fluorocarbon PVDF
Due to the strong bond energy between the chemical bonds and chemical bonds of PVDF, the coating has very good corrosion resistance and color retention. It is the most advanced product in the color coating steel coating for construction industry. The molecular weight is large and the direct bond type structure, so in addition to chemical resistance, mechanical properties, ultraviolet resistance and heat resistance are also prominent. In the general environment, the corrosion protection period can reach 20-25 years. In recent years, fluorine-containing resins copolymerized with chlorotrifluoroethylene and vinyl ester monomers have been popular in China, and are widely used in exterior walls and metal sheets of buildings. Since the content of easily hydrolyzable vinyl ester monomer and fluorine is about 30% lower than that of PVDF, there is a certain gap between the weather resistance and PVDF. The fluorocarbon coating produced by Baosteel has a PVDF content of not less than 70% (others are acrylic resins). Applicable industry: Chemical industry products have volatile characteristics, and are prone to volatile or volatile substances such as acid or alkaline. When exposed to water, dewdrops are easily attached to the surface of the color plate, causing corrosion to the coating of the color plate and possibly further corrosion. To the zinc layer or even the steel plate.
