How to Decide Coatings for PPGI Coil?
Color coated coil is hot galvanized plate, hot galvanized aluminum zinc plate, galvanized plate and other substrates, the surface pre-treatment (chemical degreasing and chemical conversion treatment), on the surface coated with a layer or several layers of organic coating, and then after baking curing products. Because coated with a variety of different colors of organic paint color steel coil plate named, referred to as color coated coil. The use of hot dip galvanized steel strip as the base material of color coating steel strip in addition to the zinc layer protection, the zinc layer of the organic coating to cover and protect the rust of the steel strip, the service life is longer than galvanized strip, about 1.5 times.
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Technical Specifications
| Parameter | Specification |
| Base Material | Galvanized Steel (GI) / Galvanized Iron |
| Thickness | 0.12mm - 1.5mm (customizable) |
| Width | 600mm - 1250mm (standard), wider sizes available upon request |
| Coating Type | Hot-dip galvanized (Zinc coating: 30g/m² - 275g/m²) |
| Coating Structure | Galvanized layer + Chemical pretreatment + Primer + Topcoat (2/1 or 2/2 system) |
| Paint Coating Thickness | 5μm - 25μm per side (depending on application) |
| Surface Finish | Glossy, Matte, Embossed, or Custom Patterns |
| Color | RAL/COLORBOND standard colors or custom colors (PVDF, PE, HDP coatings available) |
| Adhesion | ≥ 0.5N/mm² (cross-cut test per ASTM D3359) |
| Salt Spray Resistance | 500-1000 hours (ASTM B117) |
| Bending Test | No cracking at 1T-3T bend radius (ASTM D4145) |
| Hardness | Pencil hardness ≥ H (ASTM D3363) |
| Impact Resistance | ≥ 9kg·cm (ASTM D2794) |
| UV Resistance | ΔE ≤ 5 after 1000 hours QUV test (ASTM G154) |
| Standards | ASTM A755, JIS G3312, EN 10169, GB/T 12754 |
| Applications | Roofing, cladding, appliances, HVAC, furniture, automotive parts, etc. |
| Packaging | Waterproof wrapping, steel straps, wooden pallets (customizable) |
There are many PPGI coils with different paints, colors, and coating thicknesses. You can choose according to your requirements, for example, the use environment, design life, etc.
1. Coating Types
When choosing a primer, you need to consider the adhesion of the primer; while for top coating, corrosion resistance, and color retention will be more important.
There are four commonly used paints, including polyester (PE), silicone-modified polyester (SMP), high-durability polyester (HDP), and polyvinylidene fluoride (PVDF). PE coating is of good adhesion and it is widely used as a primer. While HDP and PVDF will be more suitable as a top coating because of their excellent durability and color retention.
2. Thickness of Coating
At GNEE Steel, the painting thickness is usually 5/10 ㎛. The max top paint can be 35 ㎛. Generally, the thicker the coating, the better the durability. You can choose according to the use environment. For example, a single layer of back coating is recommended for sandwich wall panels. If you have special requirements, please let us know.
3. Coating Colors
What color is the best? It mainly depends on the use environment, your preference, and market demand. For example, beauty is the first concern for civil buildings. But the corrosion resistance is more important for industrial buildings. Besides, the light color paint has a stronger heat reflection ability. Moreover, the color change in dark colors is more obvious than that in light colors.
More than that, you can also appoint the paint brands. Welcome to contact us for details!
