Types of Paints for Color Coated Steel Sheets and How to Choose

I. Types of Paints for Color Coated Steel Sheets (by Performance)

II. How to Choose the Paint

1. Consider the environment:
   • Dry inland → PE;
   • General industry → SMP/HDP;
   • Coastal/high-corrosion → PVDF.
2. Consider budget:
   
   
   Low budget → PE; Mid budget → SMP/HDP; High budget → PVDF.
3. Consider performance needs:
   
   
   UV/scrub resistance → Prioritize PVDF; Diverse colors → PE

   Why Can PVDF Color Coated Steel Sheets Last More Than 20 Years?

   PVDF color coated steel sheets can achieve a service life of more than 20 years, and the core reasons lie in the molecular structure characteristics of polyvinylidene fluoride (PVDF) coatings and the supporting high-end base plate technology, which can be specifically divided into the following three points:
   
   
   1. Superior Chemical Stability

      
      

      The main component of PVDF coatings is polyvinylidene fluoride, whose molecular chains contain high-bond-energy C-F chemical bonds with a bond energy of up to 485kJ/mol, far higher than the C-H bonds of ordinary polyester (PE) coatings. This structure can resist erosion from ultraviolet rays, acids, alkalis, salt spray, industrial waste gas and other external factors, without being prone to chalking, fading or cracking, thus blocking the path of corrosive media from contacting the base plate at the coating level.
   2. Excellent Weather Resistance and Physical Properties

      
      

      PVDF coatings have strong UV aging resistance, and can maintain stable color and performance even under long-term exposure to intense sunlight. They also boast outstanding scrub resistance, impact resistance and adhesion, and will not easily peel off due to external wear or environmental temperature differences. Qualified PVDF color coated steel sheets have a fluorine content of ≥70% and a coating thickness of ≥25μm, forming a dense protective layer.
   3. Synergistic Protection of High-end Base Plates

      
      

      PVDF color coated steel sheets are usually matched with galvalume base plates (zinc-aluminum content ≥55%), which themselves have better corrosion protection performance than hot-dip galvanized base plates. The base plate and PVDF coating form a double-layer protection system. Even if the coating is slightly damaged, the sacrificial anode protection effect of the base plate can delay rusting, further extending the overall service life.
   
   
   In addition, standardized construction and installation (such as reserving expansion joints and using supporting sealants) and regular simple maintenance can also ensure that PVDF color coated steel sheets stably achieve a service life of 20-30 years in harsh environments such as coastal areas and highly corrosive industrial zones.