PPGI coils, which stand for Pre-Painted Galvanized Iron coils, are steel coils coated with zinc for corrosion protection and then further coated with paint and primer for enhanced durability and aesthetics. This duplex system of protection makes them suitable for a variety of applications, including roofing, wall panels, and other outdoor structures. 
Elaboration:
Galvanization:
The process begins with galvanizing steel, where it's coated with a layer of zinc to prevent rust and corrosion. This zinc layer provides both cathodic and barrier protection to the base steel. 
Painting:
Following galvanization, a primer and a topcoat of paint are applied to the steel. This paint layer acts as a barrier, further reducing the corrosion rate of the zinc and enhancing the overall durability of the steel. 
Benefits:
PPGI coils offer several advantages, including:
Enhanced Corrosion Resistance: The duplex system of galvanized steel and paint provides superior protection against corrosion, making it suitable for outdoor environments. 
Aesthetic Appeal: PPGI coils come in a wide variety of colors and finishes, allowing for customized looks. 
Durability: The paint and primer layers add to the durability of the steel, making it resistant to peeling and flaking. 
Formability: PPGI coils can be easily formed and shaped, providing design flexibility for various applications. 
Applications:
PPGI coils are widely used in:
Roofing: They are a popular choice for roofing materials due to their weather resistance and durability. 
Wall Panels: They can be used for both interior and exterior wall cladding. 
Signage: PPGI coils can be used for creating durable and eye-catching signage. 
Other Applications: They are also used in agricultural buildings, fencing, and the automotive industry, among other applications.