What Is SMP Coating?

SMP coating, silicone modified polyester coating, is one of the most commonly used top paints in pre-painted steel. It combines the features of polyester resin and silicone resin, which is of excellent durability and color retention, high wear resistance, and great corrosion-weather resistance. In the general environment, its service life is more than 10 years. Therefore, the SMP color coated steel is widely used as roofing and wall panels of buildings in light industrial areas, commercial areas, residential areas, as well as areas with heavy sandstorms, steel mills, and other fields.

Ⅰ. Features of SMP Coating

Since polyester contains active groups -OH/-COOH, it is easy to react with other polymer compounds. However, silicon is a relatively stable chemical element, which can improve the light resistance and chalk resistance of polyester. The denaturation ratio with PE can be 5%-50%. The hardness, wear, and heat resistance of the modified polyester coating are improved, so that the SMP color-coated steel has excellent durability and chalking resistance.

1. Durability: Its anti-corrosion life can be as long as 10-12 years, or even longer.
2. Weathering resistance: Not afraid of climate change, cold and tropical areas also perform well, and rainy and dry seasons also have strong adaptability.
3. Corrosion resistance: Its chemical composition determines that it can well protect the substrate from damage.
4. Wear resistance: The high hardness of the coating gives it excellent wear and scratch resistance.
5. Good adhesion: It is not easy to fade and can keep the bright color for a long time. It also takes into account a certain degree of processing and molding
6. Wide range of applications: Especially as a decorative material for building roofs and exterior walls, it can also be used in other occasions that require high weather resistant coatings.

Ⅱ. What is SMP coated sheet?

Silicon modified polyester (SMP) color coated steel is sprayed on the surface of the plate with silicon modified resin coating, and then baked at high temperature and become, silicone modified polyester coating can give the steel plate better film hardness, heat resistance, abrasion resistance and durability, anti-corrosion capacity of up to 10-15 years, and better external durability and resistance to chalking, but the light retention and flexibility of the medium, the cost is medium.

Ⅲ. Applications of SMP Coating

Due to its great outdoor durability and scratch resistance, SMP color-coated steel is mainly used in areas with heavy wind and sand, as well as in mines, steel mills, and other fields. It is mainly used as roofing or wall panels of buildings or garages, warehouses in light industrial areas, commercial areas, residential areas, suburbs, and rural areas.

However, due to the poor adhesion and processability of silicone resin, SMP color-coated steel is not suitable for occasions requiring multiple forming processes.

It is mainly used in construction, industry, agriculture, and other fields. Application examples：
1. Roofs of buildings in commercial and residential areas
2. Walls in areas with severe sandstorms, light industrial areas
3. Mining houses, iron, and steel factory warehouses, and plants.
4. Roofs, doors, and windows of factories in extreme climatic areas.
5. Agricultural grain silos, greenhouses

Ⅳ. Common Paint Types

The most commonly used paints include PE (polyester), SMP (silicone modified polyester), HDP (high durability polyester), and PVDF (polyvinylidene fluoride) coatings.

1. PE coating features good adhesion and low cost, and rich colors. However, its UV resistance and chalk resistance are poor. Therefore, PE coatings are generally used in areas with less air pollution or products that need to be processed multiple times. Its service life can reach 7-8 years.

2. SMP paint has good hardness, scratch resistance, and heat resistance; as well as good durability and chalk resistance. But its softness is poor and its cost is medium. Its service life can be as long as 10-12 years. But SMP coated steel is not suitable for use in forming and processing, and most of them are used as roofing and exterior walls.

3. HDP paint has excellent color retention and UV resistance, excellent outdoor durability and chalk resistance, good film adhesion, rich colors, and excellent cost performance. It promises a 15-year warranty. Hence, HDP painted steel is ideal for light steel structure buildings with high requirements for UV resistance.

4. PVDF coating has superior corrosion resistance, excellent color retention, and UV resistance. It also has excellent outdoor durability and chalk resistance, excellent solvent resistance, and dirt resistance. Its service life is more than 20 years in a normal environment. But it has limited color and its cost is high. They are mainly used in chemical plants, power plants, steel plants, commercial and public buildings, such as high-speed railway stations, etc.

Below is a table for your reference.

Paint Types	Hardness	Bending performance	Corrosion resistance	Weather resistance	Cost
PE	Excellent	Good	Good	Great	Low
SMP	Good	Medium	Great	Excellent	Medium
HDP	Good	Excellent	Great	Excellent	Medium
PVDF	Medium	Excellent	Excellent	Excellent	High

Ⅴ. How to Choose Paints for Different Applications?

1. Steel plants and power plants: PE color-coated steel is not recommended.

2. The smelting plant has strong corrosion resistance, and it is better to choose PVDF color-coated coils.

3. Cement plants are seriously polluted by dust, so HDP or PVDF coated steel or color coated steel with self-cleaning effects is more suitable.

4. Machinery factories/Warehouses: In general, PE coated steel is widely used. If there are boilers or other corrosive substances, choose SMP, HDP, and PVDF coatings.

5. Animal husbandry: HDP coating is recommended.

6. Public buildings: It is recommended to choose HDP and PVDF paints with high-strength and high-zinc layer base metal.

7. Home appliances: The color coated steel for home appliances mainly uses VCM and PCM coated steel sheets.

8. Office furniture: Pay more attention to the processing performance of the material and the cut area.

9. The automotive industry: has more and more demands for galvanized sheets, and the requirements for complete vehicles and accessories are quite different. Choose appropriate galvanized products according to design requirements.

Ⅵ. What is SMP Coating?

SMP’s full name is Silicone Modified Polyester. It mainly composed of polyester resin, silicone resin, pigment, filler, additives, and so on. This coating can significantly improve the sunlight and heat resistance of polyester coatings by introducing silicone resin, so that it can maintain stable color and performance for a long time.

Ⅶ. SMP coated galvanized steel supplier-Wanzhi Steel

At Wanzhi Steel, the coatings, PE, SMP, HDP, and PVDF, are all available. Besides, we also offer color coated steel with special uses purposes, such as antistatic color coated coils, nano coated steel, antibacterial steel, etc. More than that, we can offer different coating thicknesses, coating methods, colors, patterns, base metals, etc. Welcome to contact us for more details!