Prepainted Galvanized Corrugated Sheet

Edge Protection Systems
Coil edge integrity is preserved through multi-stage protection: Laser trimming creates burr-free edges with Ra<0.8µm, followed by electrochemical deburring removing micro-imperfections. Zinc-rich epoxy coatings (75-95% Zn) are electrostatically applied at 100kV to edges only, achieving 15-25µm DFT with wrap-around coverage >0.5mm onto both surfaces. Cure-on-fly IR ovens (400°C) crosslink coatings in 8 seconds. For Galvalume® substrates, chromate-free zirconium passivation creates 150nm conversion layers at edges. Final inspection uses 10µm-resolution eddy current sensors detecting coating holidays.

This edge technology delivers quantifiable corrosion resistance:

• Salt Spray Performance: >1,500hrs to red rust at cut edges (ISO 9227)

• Fillet Corrosion Protection: Undercutting <0.3mm after VDA 621-415 cycling

• Galvanic Isolation: Edge coating resistivity >10¹² Ω·cm prevents bimetallic corrosion

• Forming Survivability: Coating flexibility passes 180° bend tests (ASTM D4145)
  Automotive hemming trials confirm edge integrity after flange compression to 0.1mm gap - no corrosion initiation after 80 cycles of GM 9540P testing. The system reduces edge-related warranty claims by 92% in coastal applications. Electrochemical impedance spectroscopy (EIS) shows |Z| >10⁹ Ω·cm² after 1000hrs humidity exposure, outperforming traditional sealants by 3 orders of magnitude.