As a professional manufacturer with 20 years of experience in producing color coated coils in East China, Aoguan Thin Steel is well aware that the zinc layer is the core foundation of the performance of color coated plates. The zinc layer not only directly determines the anti-corrosion ability of the substrate, but also affects the processability, durability, and final application effect of color coated products. The following is a specific analysis:

1、 The key role of zinc layer

1. Anti corrosion barrier

Cathodic protection: The electrode potential of zinc is lower than that of iron, and it sacrifices itself first to form protection in corrosive environments (electrochemical corrosion prevention).

Physical isolation: The dense zinc layer can block moisture, oxygen, and contact with the steel substrate, delaying corrosion (especially suitable for high humidity environments along the East China coast).

2. Enhance coating adhesion

The fine roughness formed on the surface of the zinc layer (such as zinc flower structure) provides better adhesion anchor points for color coating, reducing the risk of coating peeling.

3. Weather resistance extension

High quality zinc layer can reduce the volume expansion of the substrate caused by corrosion, avoid coating cracking (improve the service life of the product in outdoor buildings, industrial plants, and other scenarios).

2、 The influence of zinc layer parameters on color coated plates

3、 Quality control of zinc layer on Aoguan thin steel

Based on the industrial chain advantages of the three major production bases in East China, we ensure the performance of the zinc layer through the following measures:

1. Raw material selection: Pure zinc ingots are used, and the content of impurities such as lead and cadmium is controlled to be ≤ 0.01%.

2. Process control: The temperature control accuracy of the hot-dip galvanizing line is ± 1 ℃ to avoid embrittlement of the zinc layer.

3. Testing standard: Online X-ray thickness gauge+salt spray test to ensure that the zinc layer of each roll of color coated plate meets the standard.

4、 Provide customers with selection suggestions

1. Building roof/wall: Z120-Z180 zinc layer+PVDF coating is recommended, with a corrosion resistance period of over 20 years.

2. Home appliance panel: Choose Z60-Z90 zinc layer+environmentally friendly coating, balancing cost and flatness requirements.

3. Industrial facilities: It is recommended to use zinc coating above Z200 and epoxy primer to resist chemical corrosion.