Environmental factors affecting color-coated panels
Faced with a wide variety of coating types, how should we choose? Let me introduce several environmental factors that affect the use of color-coated boards.
1. Temperature
The coating is easy to soften at high temperature, and the corrosive medium is easy to adhere. It is easy to penetrate into the substrate, the oxygen content in the water will increase at high temperature, and the corrosion rate will increase at a certain temperature.
2. Humidity
The corrosion of the substrate at the cut and processing damage of the color-coated board belongs to electrochemical corrosion, and low humidity is not easy to form a corrosion battery (ie electrochemical circuit).
3, The temperature difference between day and night
The large temperature difference is easy to condense, forming a galvanic corrosion condition on the bare metal. In addition, the large temperature difference also leads to frequent cold and hot deformation of the coating, which will accelerate the aging and looseness of the coating, and the external corrosive medium will easily penetrate into the substrate.
4. Sunshine time and intensity
Orientation and slope affect the duration of sunshine and thus the durability of the coating. The slope also affects the settling time of corrosive media or dust on the steel plate. Sunlight is electromagnetic waves, which are divided into gamma rays, X-rays, ultraviolet rays, visible light, infrared rays, microwaves and radio waves according to their energy and frequency. Waves and radio waves have low energy and do not interact with matter. Infrared is also a low-energy spectrum. It can only stretch or bend the chemical bonds of substances, but cannot break them. Visible light gives everything rich colors. The UV spectrum is a high-frequency radiation, which has greater destructive power than the low-energy spectrum. As we know, skin dark spots and skin cancer are caused by the sun’s ultraviolet rays. Similarly, UV can also break the chemical bonds of substances, causing them to break. This depends on the UV wavelength and the chemical bond strength of the substance. X-rays have penetrating effects. Gamma rays can break the chemical bonds of substances and generate free charged ions. These are fatal to organic matter. Fortunately, these rays are very few in sunlight. Therefore, it can be seen from the above that the sunshine time and intensity affect the stability of the coating structure, especially in areas with strong ultraviolet rays.
5. Rainfall and acidity
Rainfall acidity is undoubtedly detrimental to corrosion resistance. However, rainfall has a dual effect. For wall panels and roof panels with large slopes, rainfall can clean the surface of steel plates and wash away surface corrosion products. However, for roof panels with low slopes and areas with poor drainage, large rainfall will It is easy to cause corrosion to increase.
6. Wind direction and speed
The effect of wind direction and wind speed is similar to that of water, and they are often accompanied. It is a test for the connection of materials, because the wind will cause the connection to loosen and rainwater will penetrate into the interior of the building.
7. Corrosion and sedimentation
For example, chloride ions, sulfur dioxide, etc. have an acceleration effect on corrosion, and these sediments mostly occur at the seaside and in areas with serious industrial pollution (such as power plants, smelters, etc.).