Prepainted steel refers to colored metal materials with organic coating on the surface of the metal material as the substrate, common prepainted steel is prepainted galvanized steel, prepainted galvalume steel, prepainted aluminum, prepainted stainless steel, and so on. Generally, the coatings used to coat steel are functional coatings, so they are widely used in various industries such as architecture, industry, transport, education, advertising, infrastructure, and so on.
What is the Composition Structure of Prepainted Steel?
The structure of Prepainted steel is very simple and consists of five layers: metal substrate, metal coating, chemical conversion layer, primer, and top coat.
- Substrate: cold rolled steel, hot rolled steel, aluminum, etc.
- Metal coating: zinc, aluzinc alloy layer protects the steel from oxygen, moisture, acids, and alkalis.
- Chemical conversion layer: improves adhesion.
- Primer: increases the adhesion of the coating and enhances the corrosion resistance of the steel.
- Topcoat: Enhances the weathering, corrosion, temperature, and aesthetics of the steel.
How Many Types of Prepainted Steel Top Coated?
Prepainted steel topcoats play a protective and decorative role for steel, topcoats are generally used with anti-corrosion, weathering, UV resistance, abrasion resistance, etc., in the outdoor as well as some marine, and industrial areas to maintain the performance of steel stability, in different coatings corrosion-resistant life ranging from 10 to 30 years.
| Coating | PVDF | SMP | HDP | PE |
| Anti-corrosion | Outstanding | Good | Excellent | Good |
| Weathering | Outstanding | Great | Great | Good |
| UV Resistance | Outstanding | Great | Great | Good |
| Self-cleaning | Great | Great | Excellent | Good |
What are the Types of Prepainted Steel Back Coated?
The purpose of the primer, whether on galvanized or galvalume steel, is to increase the adhesion of the coating to the steel substrate on the one hand, and to increase the corrosion resistance of the steel on the other hand. The choice of primer material is generally based on the application, processing, and topcoat.
- Epoxy primer: good adhesion, water resistance, alkali resistance, chemical resistance.
- Polyester primer: excellent adhesion, good toughness, general water resistance.
- Acrylic primer: good adhesion, good toughness, low-temperature curing.
- POLYHYDRATE primer: good chemical resistance, durability, toughness, medium adhesion.
What are the Advantages of Color Coated Steel?
- Increase the decorative properties of the steel, the coating is colorful and the surface can be designed with various patterns and motifs.
- Extend the service life of galvanized steel/galvalume steel and other metal materials.
- Improve the weather resistance and durability of the steel, and maintain the stability of the steel in high temperature and ultraviolet ray areas.
- Reduce maintenance costs, organic coating surface smooth and easy to clean and maintain.
- Wider use, in some humid, corrosive industrial areas can also be used.
How do Maintain the Prepainted Steel Coating?
The adhesion, weathering, and UV resistance of coatings vary from material to material and can cause discoloration, peeling, and scratches when used in different environments. To maintain the stability of prepared metal steel, it is necessary to carry out regular maintenance on the surface of the steel.
- Clean the surface of the steel to avoid moisture and rusting caused by the accumulation of debris.
- Avoid friction and cuts during processing or use, and protect the paint film on the surface of the steel.
- Avoid humidity during storage. If it is rained or watered, dry it in time.
- Avoid direct contact with chemicals.
How to Choose the Coating Material for Steel?
If your PPGI/PPGL/PPAL colour coated steel is rusting, mottling or even peeling off during use, it is possible that the coating material is not suitable for the local environment. When choosing the coating material, it is necessary to consider the climate, ultraviolet intensity, often contact with the material, processing technology, the use of the environment, and so on.
- PVDF coatings are recommended for high-temperature and UV regions or high-class commercial buildings.
- PE coatings are recommended for indoor and general outdoor environments.
- Roofs and facades of buildings that do not require multiple deep processing can be coated with SMP.
- HDP coatings can be used for outdoor buildings, transport facilities, etc.
Where to Buy Organically Coated Colour Coated Steel?
Wanzhi Group produces metal-coated steel: galvanized steel, galvalume steel, and ZAM steel, with color-coded production lines, with a wide range of production: primers (epoxy, polyester, acrylic, and polyhydrogen ester), top coats (PE/SMP/PVDF/HDP), paint films (top 10–40 microns, back5-20 microns.). The minimum order quantity is 10 tonnes, average annual production is 600,000 tonnes. If you need customized coated steel for your project, then Wanzhi Group is the partner you are looking for!
