Color‑Coated Coil

Color‑Coated Coil (pre‑painted steel coil), commonly known as color steel coil, mainly includes PPGI and PPGL. It adopts hot‑dip galvanized GI or Galvalume GL metallic‑coated steel as substrate. Produced on continuous coil‑coating line: degreasing, chemical conversion treatment, primer & top‑coat application, baking‑curing. Organic protective‑decorative coating is formed on strip surface. Combine mechanical strength of steel, anti‑rust performance of metallic coating and weather‑resistance, corrosion‑resistance & decorative colors of organic paint. Can be directly profiled and bent without on‑site painting. Widely used for building envelopes, home‑appliance, transportation and ventilation components.

Product distinction

‑PPGI Color‑Coated Coil: Substrate hot‑dip galvanized GI, zinc coating Z60‑Z275 g/m². Good sacrificial cathodic protection at cut‑edges, excellent bending performance, mainstream for ordinary inland projects. ‑PPGL Color‑Coated Coil: Substrate Galvalume GL (55 %Al‑43.4 %Zn‑1.6 %Si), AZ70‑AZ150 g/m². Superior atmospheric corrosion‑resistance, heat‑resistance and UV‑resistance. Preferred for coastal salt‑spray & industrial zones. Weaker sacrificial protection at cut‑edges compared with PPGI.

1. Main Types

1. By top‑coat paint system

‑PE Polyester: Cost‑effective, general construction, outdoor service life 8‑12 years. ‑SMP Silicone‑Modified Polyester: Better anti‑chalking than PE, for factory roofing. ‑HDP High‑Durability Polyester: Medium‑long‑term weather resistance, service life 12‑18 years. ‑PVDF Polyvinylidene Fluoride: High UV‑resistance, premium coastal projects, service life 20‑25 years.

2. By substrate strength grade

‑DX51D: Ordinary profiling; ‑DX52D: General drawing; ‑DX53D: Deep‑drawing components; ‑TS250GD / TS350GD / TS550GD: High‑strength structural roof & wall panels.

3. Size range

Thickness:0.15‑2.0 mm; width:600‑1500 mm; coil inner diameter:508 mm / 610 mm; coil weight:3‑10 tons. Available as cut‑to‑length sheets or slit strips. Top‑coat 15‑30 μm, primer 5‑10 μm, back‑paint 5‑10 μm. Custom colors per RAL color chart; wood‑grain, stone‑grain printed coils available.

2. Production Process

Uncoiling → Degreasing & cleaning → Chemical conversion treatment → Primer coating → Baking‑curing → Top‑coat coating → Baking‑curing → Cooling → Coiling → Final inspection.

3. Key Features

‑Continuous coil‑coating in factory delivers uniform & stable paint film, far better than manual on‑site painting. Direct profiling & bending, high construction efficiency. ‑PPGI: Strong cut‑edge sacrificial protection, good process adaptability, cost‑effective for inland projects; limited service‑life under salt‑spray environment. ‑PPGL: 2‑4 times longer corrosion‑resistant life than PPGI under equal coating mass; excellent heat‑resistance & heat reflectivity. Edge sealing is recommended after cutting. ‑Common features: Wide color options, matte/glossy/printed finishes customizable. Avoid impact & scratch of paint film during transport & storage. ‑Limitations: Rust will spread from paint‑film scratches; avoid hard‑object abrasion during fabrication & installation.

4. Typical Applications

Steel‑structure factory & warehouse roofing & wall panels, profiled tiles, fencing; sandwich‑panel skins; home‑appliance housings, electrical cabinets; ventilation ducts; containers, carriage interiors; billboards, decorative components. Choose PPGI for ordinary inland sites; choose PPGL for coastal, salt‑spray and industrial corrosive zones.

5. Standards

‑China: GB/T 12754‑2019 Color‑coated steel sheets and strips ‑International: EN 10169, ASTM A755M, JIS G 3312, JIS G 3318 ‑Russia / CIS: ГОСТ Р 52146‑2003. EAC declaration required for EAEU export.

6. Selection Guidance

1. Inland factories with limited budget: PPGI with Z100‑Z180 zinc coating, PE/SMP top‑coat.
2. Coastal, salt‑spray, industrial zones: PPGL with AZ100‑AZ150 Al‑Zn substrate, HDP/PVDF top‑coat.
3. Complex bent profiles: prefer PPGI. Edge‑sealing treatment is suggested after PPGL cutting.
4. Order specification: substrate grade, metallic‑coating mass, paint system, paint‑film thickness, RAL color number, gloss. Require MTC report, adhesion, T‑bend and salt‑spray test certificates.
5. Adequate packing protection; no dragging during loading/unloading to prevent paint‑film scratch.

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