PE (polyester) is the economical standard for 5–10 year service; SMP adds 10–15 years for a modest premium; HDP (high-durable polyester) reaches 15–20 years with better flexibility; PVDF is the premium 20–25 year system for coastal and architectural work. All four are available on our PPGI coils in RAL colors, top coats 15–30 µm. Tell us your environment — we'll spec the right system.
"PPGI" only says the coil is pre-painted galvanized — the paint system decides how it ages. Two coils of the same thickness and RAL color can differ by a decade of service life depending on whether they carry PE or PVDF. Here is how the four systems actually compare.
The Four Systems Compared
| Property | PE (Polyester) | SMP (Silicone-modified) | HDP (High-durable PE) | PVDF |
|---|---|---|---|---|
| Outdoor life (moderate climate) | 5–10 years | 10–15 years | 15–20 years | 20–25 years |
| Top coat thickness | 15–20 µm | 18–25 µm | 20–30 µm | 20–30 µm |
| Gloss retention | Fair | Good | Very good | Excellent |
| Chalk resistance | Fair | Good | Very good | Excellent |
| Flexibility / forming | Good | Moderate | Good | Good |
| Corrosion resistance | Basic | Good | Very good | Excellent |
| Relative price | 1.0× | 1.1–1.2× | 1.15–1.25× | 1.2–1.4× |
| Best for | Budget roofing, indoor panels | General roofing, industrial walls | Coastal buildings, premium roofing | Architectural facades, coastal, high-UV |
How to Choose: Four Questions
- How far from the sea? Within ~2 km of coastline or on islands: PVDF or HDP. Inland: SMP usually suffices for roofing.
- Design life of the building? Temporary structure or 5-year lease: PE. 15+ year asset: HDP/PVDF.
- Corrosive environment? Chemical plants, livestock buildings (ammonia), salt works: step up two classes.
- Aesthetics matter? Architectural facades and visible walls keep gloss far longer with PVDF.
What to Put on the Proforma Invoice
- Paint system + top coat thickness (e.g. "PVDF 25 µm top + 5 µm primer, back coat 8 µm")
- Substrate: DX51D+Z with zinc weight (e.g. Z120) — the paint protects the paint, zinc protects the steel
- Color: RAL number or color chip, gloss level (high/matte)
- Base thickness and coating tolerance (e.g. 0.50 mm ± 0.02)
- Warranty statement from the coating line (10/15/20-year systems available from prime paint brands)
Paint brand matters
Prime paint lines (Beckers, PPG, Nippon and first-tier Chinese systems) age predictably; no-name paints can chalk in 2–3 years. We state the paint system on the PI and it shows in the MTC/test report.
Wood grain & special finishes
Wood-grain, matte and textured finishes are available in PE and HDP systems for fencing, ceilings and decorative panels.
About the Source
Foshan Nikasteel International Trade Co., Ltd. — Foshan, Guangdong. PPGI/PPGL coils in PE, SMP, HDP and PVDF, RAL colors and wood-grain finishes, 0.13–1.5 mm, shipped corrugated or flat to 50+ countries since 2016. MOQ 5 t, EN 10204 3.1 MTC.
Last updated: October 2026. Service lives are indicative for moderate climates.