(DPS) Dual-Layer Epoxy Anti-Corrosion Powder Coating

Surface Finish Options Overview

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 at 24h (mm)	≤6.5	SY/T 0315-2005
Negative Electrode 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.