Product Introduction:
This dual-layer epoxy powder coating system is carefully formulated using special epoxy resins and functional curing agents. The base layer, like other epoxy anti-corrosion powder coatings, offers excellent anti-corrosion properties. The outer layer, while maintaining anti-corrosion properties, enhances protective performance. Compared to a three-layer PE structure, it offers a lower comprehensive anti-corrosion cost.
Product Usage:
Suitable for complex anti-corrosion environments, especially pipelines crossing through mountainous, river, and hilly areas.
Product Features:
- Excellent adhesion between the base material and the epoxy layers.
- Strong resistance to permeation and corrosion with high curing completion rate.
- High hardness of the outer coating, dense coating, scratch-resistant, and good resistance to plant root penetration.
- Excellent high-temperature cathodic disbondment resistance and superior mechanical properties.
Powder Performance:
Powder Coating Performance Parameters
| Test Item | Technical Specification | Remarks |
|---|---|---|
| Appearance | Uniform color, no lumps | Visual inspection |
| Particle Size Distribution | Residuals ≤4.0 at 150um, ≤0.2 at 250um | Q/CNPC 38-2002 Appendix C |
| Volatile Content (%) | ≤0.6 | Q/CNPC 38-2002 Appendix B |
| Gellation Time at 205±3°C (s) | ≥12 | Q/CNPC 38-2002 Appendix A |
| Curing Time at 230°C (min) | ≤3 | SY/T 0315-2005 |
| Magnetic Substance Content (%) | ≤0.002 | GB/T 6570 |
Cured Powder Coating Performance Parameters
| Test Item | Technical Specification | Remarks |
|---|---|---|
| Appearance | Smooth, uniform color, no bubbles, no cracks, allows slight orange peel | Visual inspection |
| Adhesion (Grade) | 1-2 | SY/T 0315-2005 |
| Negative Electrode剥离 at 24h (mm) | ≤6.5 | SY/T 0315-2005 |
| Negative Electrode剥离 at 28d (mm) | ≤8 | SY/T 0315-2005 |
| Cross-sectional Crack Rate | 1-4 | SY/T 0315-2005 |
| Coating Surface Porosity Rate | 1-4 | SY/T 0315-2005 |
| Bending Resistance (3°) | No cracks | SY/T 0315-2005 |
| Volume Resistivity | ≤1*10¹³ | GB/T 1410 |
| Electric Strength (MV/m) | ≥30 | GB/T 1408.1 |
| Impact Resistance (1.5J at -30°) | No leakage points | SY/T 0315-2005 |
| Chemical Resistance | Qualified | SY/T 0315-2005 |
| Wear Resistance (Abrasion Method) | ≤3 | SY/T 0315-2005 |
| Salt Spray Test (1000h) | Coating shows no change | GB/T 1771-1991 |
Execution Standard:
Q/CNPC 38-2002 “Technical Specification for Double Layer Fusion Bonded Epoxy Powder Coating on Steel Pipes”
Curing Conditions:
| Property | Specification | Remarks |
|---|---|---|
| Temperature | 200-230°C for 3-1.5 minutes | Medium-frequency heating recommended |
Application Parameters:
| Parameter | Specification | Notes |
|---|---|---|
| Applicable Equipment | Frictional charging spray, corona electrostatic spray | |
| Film Thickness | 250-500um | Adjustable according to workpiece requirements |
Storage Period:
- The product can be stored for 6 months in dry conditions below 30°C.
- The used coating must be re-sealed immediately to prevent moisture absorption affecting performance.
- Packaging: 20kg paper boxes lined with plastic bags.
Health and Safety:
- The product is non-toxic and non-flammable, but follow GB15607-1995 coating operation safety regulations when using.
Precautions:
- The product is not recommended for outdoor use, as fading and chalking may occur with long-term outdoor exposure.
- The steel pipe surface should be free of oil and moisture, with surface treatment quality reaching Sa21/2 level (GB/T8923), anchor pattern depth should be 40-100um, and the surface should be cleaned of dust and abrasives.
- The product should be stored in a ventilated, dry, indoor environment below 30°C, away from heat sources, corrosive chemicals, and solvents, avoiding strong light; the maximum stacking height should not exceed 5 layers; avoid long-term pressure, ensure the packaging is sealed to prevent clumping and moisture absorption, affecting fluidization performance.
