As a common building material, color steel plate is widely used because of its beauty and durability. However, in the process of using, sometimes the phenomenon of color fading occurs, what is the cause of this? And how to prevent it? 

1.What is color steel plate

color steel plate, full name “color coated steel plate”, is made of metal substrate (commonly galvanized steel, aluminum or stainless steel plate) after surface degreasing, phosphating and other pretreatment, coated with one or more layers of organic coatings (such as polyester, silicone-modified polyester, fluorocarbon and so on), and then baked at high temperature and cured into a composite material. This kind of steel plate not only has the strength and rigidity of ordinary steel plate, but also has better aesthetics and corrosion resistance due to the color coating on its surface. The production process of color steel plate mainly includes steel pretreatment, coating preparation, painting, drying and other steps to ensure the close combination between the coating and the steel plate as well as the uniformity and durability of the coating.

2. Characteristics of color steel plate

(1) Aesthetics: color steel plate has a rich selection of colors and gloss, which can be customized according to different needs and scenes, making the building or product more aesthetically pleasing and personalized.

(2) Corrosion resistance: the color coating on the surface of the color steel plate has good corrosion resistance, can effectively resist the corrosive medium in the atmosphere, prolong the service life of the steel plate.

(3) Easy processing: color steel plate has good plasticity and processing performance, convenient for cutting,

 bending, punching and other processing operations, to meet the needs of a variety of complex shapes.

(4) environmental protection: with the improvement of environmental protection consciousness, color steel plate manufacturers began to use environmentally friendly paint and production process, reduce the pollution emission in the production process, make color steel plate more environmentally friendly.

3. Reasons for color steel plate fading

(1) ultraviolet radiation

-Destruction of coating structure:

Long-term exposure to sunlight, the energy of ultraviolet rays will destroy the molecular structure of the surface coating of color steel plate. For example, the organic components in the coating may undergo photo-oxidation reaction, resulting in chemical bond breakage, so that the coating gradually loses its original color and luster. Like in the outdoor environment, especially in the area of strong sunlight, the color steel plate will be obviously faded after a long time of ultraviolet radiation.

-Accelerates the aging process:

Ultraviolet rays accelerate the aging of the color steel plate coating, making it weak and fragile. As aging intensifies, the coating's ability to keep the color decreases, resulting in fading. For example, in some color steel plate roofs that have not taken protective measures, after several years of sun exposure, the original bright color will become dull.

(2) Influence of climate conditions

-Temperature changes:

Large temperature changes will lead to thermal expansion and cold contraction of color steel plate coating. Frequent thermal expansion and contraction may cause minor cracks in the coating, which not only affect the appearance, but also make the coating more susceptible to the erosion of external factors, which will lead to color fading. For example, in areas where there is a big difference in temperature between day and night, the color fading problem of color steel plate may be more obvious.

-Humidity and rain:

A high humidity environment will prompt hydrolysis reaction on the surface of the coating, affecting the stability of the color. At the same time, rain water will also take away some pigment components in the coating, leading to color fading. Especially in areas with frequent acid rain, acidic rainwater has a stronger corrosive effect on the color steel plate coating, accelerating the process of fading.

(3) Chemical substance erosion

-Atmospheric pollution:

Pollutants in the air, such as sulfur dioxide, nitrogen oxides, etc., will have a chemical reaction with the color steel plate coating, resulting in color change and fading. For example, in the industrial area, a large amount of exhaust gas emission may cause serious chemical erosion to the nearby color steel plate, making it fade rapidly.

-Corrosive chemical substance contact:

If the surface of color steel plate comes into contact with some corrosive chemical substances, such as strong acid, strong alkali, etc., it will directly damage the color and structure of the coating and cause fading. For example, in the vicinity of chemical factory, the color steel plate may be affected by the leaked chemical substances and fade.

(4) Coating quality problems

-Improper choice of pigment:

If poor quality or non-durable pigments are used in the production process, the color durability of the color steel plate will be affected. These pigments may fade in a short time. For example, some low-priced color steel products use poor-quality pigments in order to reduce costs, resulting in noticeable fading after a short period of use.

-Insufficient coating thickness:

Insufficient coating thickness will make the pigment unable to get sufficient protection, and it will be more likely to be affected by external factors and fade. For example, some jerry-built color steel plate products with thin coatings cannot provide effective protection and are prone to fading.

4.How to prevent color steel plate fading

(1) Selection of high-quality coating

When purchasing color steel plate, you should give preference to products with high-quality coating. High-quality coating is not only colorful and long-lasting, but also has stronger weather resistance and corrosion resistance, which can effectively resist the erosion of the external environment.

(2) Reasonable selection according to the environment

Coastal and industrial areas should avoid the use of low-end polyester color steel plate, and give priority to fluorocarbon or silicon modified polyester products.

In areas with strong ultraviolet rays, it is recommended to increase the protective layer, such as sunshade coating or special protective film.

(3) Standardize construction

Avoid scratching the surface during installation, otherwise it is easy to form rust spots, which in turn accelerates the fading of color.

The joints should be well sealed to avoid long-term soaking in rainwater.

(4) Regular cleaning and maintenance

Clean it once every half a year or one year, use neutral cleaner and soft cloth, avoid using sharp tools or corrosive cleaner

For local color loss or broken places, special patching paint or anticorrosive paint can be used to repair and prevent further spread.

5. The main use of color steel plate

Color steel plate is widely used in the following fields by virtue of its performance advantages:

(1) Construction industry

- Roof and wall: commonly used in the enclosure structure of large-span buildings such as industrial workshops, warehouses, stadiums, etc. The construction efficiency is more than 50% higher than that of traditional materials.

- Partition and ceiling: office, hospital and other places use color steel plate partition wall, both fireproof (some models of fire-resistant limit of 1 hour) and sound insulation performance.

- Temporary buildings: movable houses at construction sites, disaster relief tents, etc., because they can be disassembled and reused, the cost is reduced by 30%~40%.

(2) Home appliances and furniture

- Refrigerator, washing machine shell mostly use color steel plate, rust and easy to clean.

- Cabinets, filing cabinets and other furniture using color steel veneer, beautiful and durable.

(3) Transportation

- High-speed rail, subway car interior panels commonly used color steel plate, light weight and in line with fire standards (such as EN 45545-2).

- Van box body using color steel plate can reduce weight by 15% to 20%, reduce fuel consumption.

Will the color steel plate fade? The answer is yes ---- In the process of long time use, the surface coating of color steel plate will inevitably be affected by ultraviolet rays, climate change, pollutants and other factors and fade. However, fading does not mean poor quality, but is part of the natural aging of the material.

As an important material for modern construction, the development of color steel plate is moving towards a more weather-resistant, more environmentally friendly and smarter direction. As long as you pay attention to quality and maintenance in the process of purchase and use, color steel plate is fully capable of maintaining its beauty and practical value for a long time, and continues to play an important role in the field of construction.