Understanding Color-Coated Steel Sheets in One Article

1. What is color-coated plate
Color-coated plate, full name color coated steel plate, is a composite material in which organic coating is applied to a metal substrate. It uses cold-rolled steel plate, hot-rolled steel plate or galvanized steel plate as the substrate, and undergoes surface pretreatment such as degreasing, rust removal, phosphating and other processes to enhance the adhesion of the coating to the substrate, and then evenly applies one or more layers of organic coating on the surface of the substrate by roller coating, spraying and other methods, and finally cures by high-temperature baking to form a hard and dense protective film, thereby giving the metal sheet rich colors, good corrosion resistance and other excellent properties. The thickness of the color-coated plate is usually between 0.2-2mm, and the width can reach 1250mm or even wider according to the production equipment and market demand, which can meet the diverse use requirements of different industries.
2. Characteristics of color-coated plate
Rich and beautiful appearance: color-coated plates can provide a variety of color options, whether it is fresh and elegant tones or bright and eye-catching colors, they can be customized according to the personalized needs of users. This feature greatly enhances the overall beauty and visual appeal of buildings in the field of architecture, and adds rich color elements to the urban landscape. For example, in some modern commercial buildings and residential areas, the colorful roofs and walls of color-coated panels complement the surrounding environment, creating a unique and charming architectural style.
Excellent corrosion resistance: The organic coating forms an effective barrier on the surface of the metal substrate, which can prevent moisture, oxygen, salt and various corrosive chemicals in the external environment from directly contacting the metal, thereby significantly improving the corrosion resistance of the metal sheet. Compared with ordinary metal sheets, the service life of color-coated panels has been greatly extended. Taking the construction industry as an example, in some coastal areas or areas with severe industrial pollution, the use of color-coated panels as building envelope materials can effectively resist the erosion of humid air and corrosive gases, reducing the maintenance cost of buildings and the risk of structural damage.
Good processing performance: Color-coated panels have similar processing performance to metal substrates, and can be cut, bent, stamped, welded and other processing operations. During the processing process, the coating is not easy to fall off or crack, and can maintain its complete appearance and performance. This enables color-coated panels to adapt to various complex design requirements and construction conditions, making it convenient for manufacturers to manufacture products of various shapes and specifications to meet the actual application needs of different industries. For example, in the electrical industry, color-coated panels can be processed into the shapes of various home appliance shells, which not only ensures the aesthetics of the products, but also ensures good processing technology.
Certain strength and rigidity: On the basis of retaining the strength and rigidity of the metal substrate, the color-coated panels further improve their overall structural performance through the synergistic effect of the organic coating. It can withstand certain external forces and is not prone to deformation or damage, meeting many application scenarios that require structural strength. For example, in some light steel structure buildings, color-coated panels, as roofing and wall materials, must not only have good decorative properties and corrosion resistance, but also have sufficient strength and rigidity to withstand the effects of natural forces such as wind loads and snow loads.
Easy installation: Because the color-coated panels themselves have good processing performance and light weight, during the installation process, construction workers can easily carry, assemble and fix them. Compared with traditional building materials, it can greatly shorten the construction period and improve construction efficiency. Taking prefabricated buildings as an example, color-coated panels, as one of the main materials for prefabricated components, are easy and quick to install on site, reducing wet operations, construction costs and environmental impact.
3. Application areas of color-coated panels
Construction industry
Roofs and walls: Color-coated panels are most widely used in building roofs and walls. Its rich colors and good weather resistance enable it to adapt to the climatic conditions and architectural style requirements of different regions. In industrial plants, color-coated roofs and walls can provide efficient waterproofing, anti-corrosion and heat insulation performance, while the characteristics of rapid construction help shorten the plant construction cycle and reduce costs. In civil buildings such as residential areas, schools, hospitals, etc., color-coated panels can create a warm and beautiful building appearance, and have good durability and maintenance convenience.
Doors and windows: Some color-coated panels can be used to make door and window frames and decorative parts. The color coating on its surface not only improves the beauty of doors and windows, but also enhances the corrosion resistance of doors and windows and extends their service life. Compared with traditional material doors and windows, color-coated board doors and windows have more diversified appearance designs, can be integrated with the overall style of the building, and have good sealing performance and thermal insulation performance.
Architectural decoration: In the field of indoor and outdoor architectural decoration, color-coated boards can be used to make decorative components such as ceilings, partitions, curtain walls, etc. For example, in the interior decoration of commercial complexes, color-coated board ceilings can create a unique spatial atmosphere through different color combinations and shape designs. In terms of building curtain walls, color-coated boards can present a texture and texture similar to natural materials such as stone and wood through special processing technology and surface treatment, enriching the decorative effect of the building facade.
Home appliance industry: In the home appliance industry, color-coated boards are mainly used to manufacture the shells of home appliances such as refrigerators, washing machines, air conditioners, and microwave ovens. The rich colors and smooth surface of color-coated boards can bring fashionable and beautiful appearance to home appliances, satisfying consumers' pursuit of product appearance quality. At the same time, its good processing performance enables the shell of home appliances to achieve complex shape design, improving the market competitiveness of products. In addition, the corrosion resistance and wear resistance of color-coated plates can effectively protect the housing of home appliances from scratches, corrosion and other damage during daily use, and extend the service life of home appliances.
Automobile industry
Automobile body: Color-coated plates are also used in automobile body manufacturing. For example, some car body covers, such as doors, hoods, trunk lids, etc., can be made of color-coated plates. Color-coated plates can not only provide a beautiful appearance for the car, but also have certain anti-corrosion properties, which helps to protect the car body structure. At the same time, compared with the traditional painting process, the use of color-coated plates can reduce the painting process in the automobile production process, reduce production costs and environmental pollution.
Automobile interior: In terms of automobile interior, color-coated plates can be used to make automobile dashboards, center consoles, door interior panels and other parts. By choosing color-coated plates of different colors and textures, a variety of interior decoration styles can be created, and the overall texture and beauty of the car interior can be improved. Moreover, color-coated plates have good formability and surface quality, which can meet the design requirements of complex shapes and high precision of automobile interiors.
Furniture manufacturing: In the furniture manufacturing industry, color-coated boards can be used to manufacture various furniture products such as tables and chairs, cabinets, wardrobes, and bookshelves. The rich colors and good wear resistance of color-coated boards make them an ideal choice for furniture surface decoration materials. Furniture made of color-coated boards not only has a fashionable appearance and long-lasting colors, but also can resist a certain degree of scratches and stains during daily use, and is easy to clean and maintain. For example, in modern minimalist style furniture design, color-coated boards are often used to create a simple and bright furniture appearance while meeting the practicality and durability requirements of furniture.
Other fields
Billboards: Color-coated boards are widely used in the production of billboards because of their bright colors and good visual effects. Whether it is a large outdoor billboard or an indoor promotional display board, color-coated boards can provide clear and eye-catching display effects to attract people's attention. At the same time, its good weather resistance can ensure that billboards are not easy to fade or deform in long-term outdoor environments, and maintain good publicity effects.
Containers: In the field of container manufacturing, color-coated boards can be used to make container bodies. The high strength and corrosion resistance of color-coated plates can ensure that the container can withstand various harsh environments and external forces during long-term transportation and storage, and protect the safety of the goods in the box. In addition, the machinability of color-coated plates makes the manufacturing process of containers simpler and improves production efficiency.
Communication tower: The tower body and auxiliary structures of some communication towers will use color-coated plates. Color-coated plates not only provide a beautiful appearance for communication towers, but also effectively prevent communication towers from rusting and corroding in outdoor environments, extend the service life of communication towers, and ensure the stable operation of communication equipment. At the same time, the lightweight characteristics of color-coated plates help to reduce the overall weight of communication towers and reduce construction and installation costs.
4. Production process and technical points of color-coated plates
Production process
Metal plate pretreatment: This is the first step in the production of color-coated plates, and the purpose is to provide a good surface foundation for subsequent paint coating. The pretreatment steps usually include degreasing, rust removal, phosphating and other processes. Degreasing is to remove oil and impurities on the surface of metal plates by chemical degreasing agents to ensure that the paint can fully contact the surface of the plates; rust removal uses pickling or mechanical rust removal to remove rust on the surface of the plates to prevent rust from affecting the adhesion and corrosion resistance of the coating; phosphating is to form a layer of phosphate chemical conversion film on the surface of the metal plates to increase the roughness of the plate surface, improve the adhesion of the paint, and further enhance the corrosion resistance of the plates.
Paint coating: The pretreated metal plates enter the coating production line for paint coating. There are two main coating methods: electrostatic spraying and roller coating. Electrostatic spraying uses a high-voltage electrostatic electric field to charge the paint particles. Under the action of the electric field force, the paint particles are evenly adsorbed on the surface of the metal plate to form a coating. This coating method can achieve uniform coating of complex-shaped plates, and the coating thickness control is relatively precise, but the equipment investment is large and the production efficiency is relatively low. Roller coating is to transfer the paint evenly to the surface of the metal plate through a roller. It is suitable for large-area, continuous flat or strip coating production, and has the advantages of fast speed and high production efficiency. During the coating process, the coating amount and coating thickness must be strictly controlled to ensure uniform coating.
Baking and curing: The metal sheet coated with the coating is sent to the baking oven for baking and curing. Under high temperature, the resin and other components in the coating undergo cross-linking reaction to form a hard and dense protective film that is firmly attached to the surface of the metal sheet. The temperature and time of baking and curing are key parameters and need to be precisely controlled according to factors such as the type of coating and coating thickness. If the temperature is too low or the time is too short, the coating cannot be fully cured, resulting in poor coating performance; if the temperature is too high or the time is too long, the coating may turn yellow and brittle, affecting the coating quality. Generally speaking, the baking and curing temperature is between 180-250℃, and the time ranges from a few minutes to more than ten minutes.
Technical points
Selection of coating: According to the different application areas and use environments of color-coated plates, it is necessary to select the appropriate type of coating. For example, in the field of building exterior use, the coating is required to have good weather resistance, corrosion resistance and light and color retention. Usually, polyester, silicon-modified polyester, polyvinylidene fluoride (PVDF) and other coatings are selected; in the home appliance industry, in order to meet the requirements of appearance and processing performance, polyester coatings for home appliances are selected. At the same time, the quality and stability of the coating are also crucial. High-quality coatings can guarantee the various performance indicators of the coating and reduce quality problems in the production process.
Control of coating process: The precise control of coating process parameters plays a decisive role in the quality of the coating. During the roller coating process, the gap and speed between the feeding roller, metering roller and coating roller should be controlled to ensure the uniform transfer of the coating and the accuracy of the coating thickness. During the electrostatic spraying process, the voltage, current, spraying distance and angle of the spray gun should be adjusted to ensure the uniformity and adhesion of the coating. In addition, the coating environment, such as temperature and humidity, needs to be strictly controlled to avoid environmental factors from having an adverse effect on the quality of the coating.
Setting of curing temperature: Curing temperature is one of the key factors affecting the performance of the coating. Different types of coatings have different curing temperature requirements, and the temperature of the baking oven must be set accurately according to the characteristics of the coating. At the same time, it is necessary to ensure that the temperature distribution in the baking oven is uniform, and avoid the situation where the local temperature is too high or too low, so as not to cause inconsistent coating curing and affect the quality of the color-coated board. Modern advanced color-coated board production lines are usually equipped with high-precision temperature control systems, which can monitor and adjust the temperature in the baking oven in real time to ensure the stability and reliability of the curing process.
5. How to choose high-quality color-coated board products
Pay attention to coating quality
Color and gloss: The coating color of high-quality color-coated boards should be bright and uniform, without obvious color difference. When choosing, you can observe whether the surface color of the color-coated board meets expectations, as well as the color consistency between different batches of products. At the same time, the gloss of the coating should be moderate and have a good visual effect. Too high or too low gloss may affect the beauty and use effect of the product. For example, in the field of architectural decoration, for some projects that pursue high-end texture, color-coated boards with matte effects may be selected, while in some occasions where eye-catching effects need to be highlighted, high-gloss color-coated boards will be selected.
Hardness and wear resistance: The hardness of the coating can be tested by methods such as the pencil hardness test. Generally speaking, coatings with higher hardness can better resist scratches and wear, and are less likely to be scratched and damaged in daily use. For application scenarios that are often subject to friction or collision, such as furniture surfaces and home appliance housings, it is particularly important to choose color-coated panels with higher hardness and wear-resistant coatings. In addition, the wear resistance of the coating can be understood by simulating wear tests in actual use environments.
Adhesion: The adhesion between the coating and the substrate is directly related to the service life and performance stability of the color-coated board. Standard test methods such as the cross-cutting method can be used to evaluate the adhesion of the coating. Coatings with strong adhesion are not easy to fall off the substrate when subjected to external forces, which can effectively ensure the overall performance of the color-coated board. In industries such as construction and automobiles, the requirements for the adhesion of color-coated board coatings are high, because products in these fields may be affected by various external forces during long-term use, such as wind, sun, rain, mechanical vibration, etc.