Application Fields

1. Construction Industry
   Widely used in building exterior walls, roofs, and interior decorations. For example, metal curtain walls, factory building roofs, and the ceilings of civil residential buildings. It is both aesthetically pleasing and can effectively resist the erosion of the natural environment, prolonging the service life of buildings.
2. Home Appliance Industry
   Used for manufacturing the outer shells of home appliances such as refrigerators, air conditioners, and washing machines. It can not only enhance the appearance texture of products but also improve the corrosion resistance and strength of the outer shells, protecting internal components.
3. Transportation
   Applied in the manufacturing of automobiles, trains, and ships. For example, some components of automobile bodies, the decorative panels of train carriages, and the interior materials of ships. It can reduce the overall weight while improving structural strength and seawater corrosion resistance.
4. Electronic Equipment
   Suitable for the manufacturing of outer shells of electronic equipment such as computer cases and server enclosures. It can ensure the heat dissipation performance of equipment and provide good electromagnetic shielding effects, protecting internal electronic components from external electromagnetic interference.

What is a Composite Material?

1. Preparation of Base Steel
   Select steel of appropriate grades, process it into the required coil specifications, and conduct surface pre - treatment to remove surface impurities and prepare for subsequent compounding.
2. Coating or Lamination of Composite Materials
   For galvanized and galvalume composite materials, hot - dip plating or electroplating processes are used to evenly coat zinc or aluminum - zinc alloy on the surface of the steel. For organic - coated composite materials, organic coatings are evenly applied to the steel surface through roll coating, spraying, etc., and then cured. In the case of lamination, pre - fabricated composite material films are tightly bonded to the steel through processes such as high - temperature and high - pressure treatment.
3. Quality Inspection and Coiling
   Conduct comprehensive quality inspections on the composite coils, including the inspection of indicators such as coating thickness, adhesion, and corrosion resistance. After passing the inspection, coil the product according to the specified inner and outer diameters and coiling requirements, and package it for storage.

Advantages of Composite Material

1. Strong Corrosion Resistance
   The composite material layers on the surface, such as galvanized, galvalume, or organic coatings, can effectively isolate air, moisture, and other corrosive media, greatly improving the corrosion resistance of steel, reducing maintenance costs and replacement frequencies.
2. Aesthetic Appearance
   Organic - coated composite steel coils have a rich variety of colors and surface textures, which can meet the personalized appearance requirements of different customers and enhance the overall aesthetic appeal and market competitiveness of products.
3. Excellent Comprehensive Performance
   Combining the high strength of steel with the special properties of composite materials, such as good processability and fire resistance (some organic coatings have a certain fire rating), enabling it to perform well in various application scenarios.
4. High Cost - performance Ratio
   Although the price is slightly higher than that of ordinary steel, due to its excellent performance, it has obvious advantages in terms of service life and maintenance costs. In the long run, it can save a large amount of costs for users.

Composite Steel Coils  vs Ordinary Steel Coils

1. Different Production Processes

• Composite Steel Coils: The production process is more complex. In addition to the basic steel processing procedures, it is also necessary to add procedures for coating, lamination, and related processing of composite materials, with higher requirements for production equipment and process control.
• Ordinary Steel Coils: The production process is relatively simple, mainly including basic procedures such as steel rolling, cooling, and coiling.

2. Different Performance Characteristics

• Composite Steel Coils: Have better corrosion resistance, decorativeness, and certain special functions (such as electromagnetic shielding, fire resistance, etc.), and can meet application scenarios with higher requirements.
• Ordinary Steel Coils: Mainly rely on the performance of the steel itself, and are relatively weak in terms of corrosion resistance and appearance decorativeness, usually suitable for occasions with relatively low requirements for these properties.

3. Different Application Scopes

• Composite Steel Coils: Mainly applied in fields with high requirements for product appearance, corrosion resistance, and comprehensive performance, such as high - end construction, home appliances, and electronic equipment.
• Ordinary Steel Coils: Widely used in general industrial manufacturing fields with relatively low performance requirements, such as ordinary machinery manufacturing and non - exposed parts of building structures.

4. Different Costs

• Composite Steel Coils: Due to the complex production process and the use of additional composite materials, their production costs are usually higher than those of ordinary steel coils.
• Ordinary Steel Coils: The production process is simple, and the raw material cost is relatively low, so the overall cost is low.

Production Process of Composite Steel Coils

1. Preparation of Base Steel

• Steel Selection and Inspection: Select suitable steel according to the expected use and performance standards of the product. For example, Q235, Q345, etc. are often selected for the construction field. After the steel arrives, strictly inspect its dimensional accuracy, hardness, chemical composition, and other indicators to ensure compliance with production requirements.
• Surface Pre - treatment: Use methods such as shot blasting and pickling to remove scale, rust, oil, and other impurities from the steel surface, and increase the surface roughness of the steel to create favorable conditions for the adhesion of subsequent composite materials. The treated steel surface needs to meet a certain cleanliness standard, such as Sa2.5 level, that is, thorough shot or grit blasting. There should be no visible grease, dirt, scale, rust, and paint coating attachments on the steel surface, and any remaining traces should only be slight spots or streaks.

2. Coating / Lamination of Composite Materials

• Galvanizing / Galvalume Process (Taking Hot - Dip Galvanizing as an Example): Immerse the pre - treated steel in molten zinc or aluminum - zinc alloy liquid. Under the action of high temperature, zinc or aluminum - zinc alloy reacts chemically with the steel surface to form a tightly - bonded intermetallic compound layer and a pure zinc (or aluminum - zinc alloy) layer. During hot - dip galvanizing, the temperature of the zinc liquid is usually controlled at 440 - 460℃, and the dipping time is adjusted according to the thickness of the steel and process requirements, generally 1 - 3 minutes. Appropriate amounts of aluminum, magnesium, and other elements are added to the plating solution to improve the structure and properties of the coating and enhance its corrosion resistance.
• Organic Coating Application (Taking Polyester Coating as an Example): First, prepare the polyester coating well and evenly coat it on the steel surface through a roller coater. During the roller coating process, strictly control the coating amount and thickness of the coating. Generally, the coating amount of the primer is 10 - 20g/m², and that of the topcoat is 20 - 30g/m². After coating, send the steel to a curing furnace and bake it at a high temperature of 180 - 220℃ for 10 - 20 minutes to cross - link and cure the resin in the coating, forming a hard, wear - resistant, and corrosion - resistant organic coating.
• Composite Material Lamination (Such as Sticking Plastic Film): Place the pre - prepared plastic film (such as PVC film) on the laminating equipment and bond it tightly to the steel surface through heating and pressurization. The heating temperature is generally controlled at 80 - 120℃, and the pressure is 0.5 - 1.5MPa. During the lamination process, ensure that there are no air bubbles or wrinkles between the film and the steel to ensure the lamination quality.

3. Quality Inspection

• Coating Thickness Detection: Use magnetic thickness gauges or eddy - current thickness gauges to measure the thickness of galvanized layers and organic coatings to ensure that the coating thickness meets the design requirements. Different application scenarios have different requirements for coating thickness. For example, the galvanized layer thickness of composite steel coils for building exterior walls generally requires 80 - 120μm, and the total thickness of the organic coating is 25 - 40μm.
• Adhesion Detection: Use methods such as the cross - hatch test and the pull - off test to detect the adhesion between the coating or the laminated material and the steel substrate. In the cross - hatch test, make a grid on the coating surface according to the standard, then stick adhesive tape and tear it off quickly, observe the coating detachment situation, and rate it according to the detachment area. In the pull - off test, use special equipment to vertically stretch the coating, measure the force required to pull the coating off the steel surface, and determine whether the adhesion meets the standard. Generally, the adhesion is required to reach grade 0 - 1 (cross - hatch test) or meet a certain pull - off force value (pull - off test).
• Corrosion Resistance Detection: Simulate the actual use environment through salt spray tests, damp - heat tests, etc., to detect the corrosion resistance of composite steel coils. During the salt spray test, place the sample in a salt spray test chamber. The salt spray concentration in the chamber is 5%, and the temperature is 35℃. The test time is set according to the product standard, generally 24 - 96 hours. After the test, observe the corrosion situation of the sample surface, such as whether red rust, blistering, peeling, etc. occur, and evaluate its corrosion resistance.

4. Coiling and Packaging

• Coiling: Coil the composite steel coils that have passed the quality inspection according to the set inner diameter, outer diameter, and coiling tension. During the coiling process, maintain stable tension to prevent defects such as loose coils and tower - shaped coils. Generally, the coiling tension is controlled at 50 - 150N/mm², and adjusted according to the material and thickness of the coil.
• Packaging: Package the coils with moisture - proof paper, plastic film, steel strapping, etc. First, wrap a layer of moisture - proof paper on the surface of the coil to prevent rusting due to moisture during storage and transportation. Then, wind the plastic film around the coil as a whole to protect and prevent dust. Finally, use steel strapping to bind the two ends and the middle part of the coil to ensure a firm package. Mark the product specifications, model, production date, manufacturer, and other information on the package for easy identification and traceability.