Color coated steel coils, also known as color coated steel coils, play an indispensable role in modern industry and construction. They use hot-dip galvanized steel sheets, hot-dip aluminum-zinc steel sheets, electro-galvanized steel sheets, etc. as substrates, undergo sophisticated surface pretreatment, including chemical degreasing and chemical conversion treatment, and then apply one or more layers of organic coatings on the surface. Finally, they are baked and cured to form. Because the surface is coated with organic coatings of various colors, the color steel coils are named after them, and are referred to as color coated steel coils.
Development History
Color coated steel sheets originated in the United States in the mid-1930s. At first, they were narrow strips of steel painted, mainly used to make blinds. With the expansion of the scope of application, as well as the development of the coating industry, pretreatment chemical reagents and industrial automation technology, the first wide-band coating unit was built in the United States in 1955, and the coatings also developed from the initial alkyd resin paint to types with stronger weather resistance and inorganic pigments. Since the 1960s, the technology has spread to Europe and Japan and developed rapidly. The development history of color-coated coils in China is about 20 years. The first production line was introduced by Wuhan Iron and Steel Corporation from David Company in the UK in November 1987. It adopts advanced two-coating and two-baking process and roller coating chemical pretreatment technology, with a designed annual production capacity of 6.4 tons. Then, Baosteel’s color coating unit equipment was put into production in 1988, introduced from Wean United in the United States, with a maximum process speed of 146 meters per minute and a designed annual production capacity of 22 tons. Since then, major domestic steel mills and private factories have devoted themselves to the construction of color-coated production lines. The color-coated coil industry has developed rapidly and has now formed a mature and complete industrial chain.
Product Features
1. Decorative: Color-coated coils have rich and diverse colors, which can meet the pursuit of aesthetics in different industries. Whether it is fresh and elegant or bright and eye-catching, it can be easily achieved, adding unique charm to products and buildings.
2. Corrosion resistance: The specially treated substrate, coupled with the protection of organic coatings, has good corrosion resistance, can resist the erosion of harsh environments, effectively extend service life, and reduce maintenance costs.
3. Mechanical structural properties: Inheriting the mechanical strength and easy-to-form properties of steel plates, it is easy to process and install, can adapt to various complex design requirements, and is convenient to make products of different shapes and specifications.
4. Flame retardancy: The organic coating on the surface has certain flame retardancy. In the event of a fire, it can prevent the spread of fire to a certain extent, thereby improving the safety of use.
Coating structure
1. 2/1 structure: The upper surface is coated twice, the lower surface is coated once, and baked twice. The single-layer back paint of this structure has poor corrosion resistance and scratch resistance, but good adhesion, and is mainly used in sandwich panels.
2. 2/1M structure: The upper and lower surfaces are coated twice and baked once. The back paint has good corrosion resistance, scratch resistance, processing and forming properties, and good adhesion, and is suitable for single-layer profiled panels and sandwich panels.
3. 2/2 structure: The upper and lower surfaces are coated twice and baked twice. Double-layer back paint has good corrosion resistance, scratch resistance and processing formability. Most of them are used for single-layer profiled panels. However, its adhesion is poor and it is not suitable for sandwich panels.
Substrate classification and application
1. Hot-dip galvanized substrate: hot-dip galvanized color-coated sheet is obtained by coating organic coating on hot-dip galvanized steel sheet. In addition to the protective effect of zinc, the organic coating on the surface also plays a role in isolation protection and rust prevention, and its service life is longer than that of hot-dip galvanized sheet. The zinc content of hot-dip galvanized substrate is generally 180g/m² (double-sided), and the maximum galvanizing amount of hot-dip galvanized substrate for building exterior is 275g/m². It is widely used in construction, home appliances, electromechanical, transportation and other industries.
2. Alu-zinc-coated substrate: more expensive than galvanized sheet, with better corrosion resistance and high temperature resistance, it can effectively prevent rust even in harsh environments, and its service life is 2-6 times that of galvanized sheet. It is relatively more suitable for use in acidic environments and is often used in buildings or special industrial environments with high durability requirements.
3. Cold-rolled substrate: equivalent to a bare plate, without any protective layer, with high requirements for coating, the lowest price, the heaviest weight, suitable for home appliance manufacturing fields with high surface quality requirements and low corrosion environments.
4. Aluminum-magnesium-manganese substrate: more expensive than the previous materials, with the characteristics of light weight, beautiful, not easy to oxidize, corrosion resistance, etc., suitable for coastal areas or industrial buildings with high durability requirements.
5. Stainless steel substrate: the highest cost, heavy weight, high strength, high temperature resistance, corrosion resistance, suitable for high temperature, high corrosion and high clean environment, such as chemical, food processing and other special industries.
Main uses
1. Construction industry: commonly used in the roofs, walls and doors of industrial and commercial buildings such as steel structure factories, airports, warehouses, freezers, etc., which can not only provide beautiful appearance, but also effectively resist wind and rain erosion and extend the service life of the building. For example, the roofs and walls of large logistics warehouses can reduce maintenance costs and enhance the overall image of the building while ensuring structural strength.
2. Home appliance industry: It is widely used in the manufacture of refrigerators, freezers, bread machines, furniture and other home appliances. Its rich colors and excellent corrosion resistance add texture and grade to home appliances, meeting consumers’ dual needs for beauty and practicality.
3. Advertising industry: It can be used to make various billboards, display cabinets, etc. With its beautiful and durable characteristics, it can still maintain a good display effect in complex outdoor environments and attract people’s attention.
4. Transportation industry: In the manufacture and maintenance of vehicles such as cars, trains, and ships, it is used for the decoration and protection of car bodies, carriages and other parts, which not only improves the appearance of the vehicles, but also enhances their corrosion resistance.
Post time: Jun-19-2025