PPGI and PPGL Steel Sheets: What's the Difference?

Pre-Painted Galvanized Iron Steel, also called PPGI, and Pre-Painted Galvalume Steel, PPGL, are two different types of color coated steel. Both PPGI and PPGL are used in a wide range of industries such as construction, transportation, and the appliance industry.

 

Pre-Painted Galvanized Iron Steel, also called PPGI, and Pre-Painted Galvalume Steel, PPGL, are two different types of color coated steel. Both PPGI and PPGL are used in a wide range of industries such as construction, transportation, and the appliance industry. They are both very similar but still have unique differences.

 

Various Substrate Types:

 

Galvanized steel, known as PPGI, features a complete zinc coating, whereas Galvalume steel, referred to as PPGL, is coated with aluminum, zinc, and a small quantity of silicone. This results in enhanced corrosion resistance and durability compared to the standard galvanized coating. This fundamental disparity between PPGI steel and PPGL is the primary reason for differences in various aspects such as weight, lifespan, appearance, cost, and applications.

 

Weight Disparity Between PPGI and PPGL:

 

Due to the lower specific weight of aluminum compared to zinc, the aluminum-zinc coating on PPGL will be lighter for the same coating thickness. Consequently, the Al-Zn coating, with the same weight, can cover 3% more area than PPGI.

 

Corrugated steel sheet

 

 

Weight Disparity Between PPGI and PPGL:

 

Due to the lower specific weight of aluminum compared to zinc, the aluminum-zinc coating on PPGL will be lighter for the same coating thickness. Consequently, the Al-Zn coating, with the same weight, can cover 3% more area than PPGI.

 

Service Life:

 

Both zinc and aluminum-zinc coatings serve to safeguard metal against rusting, extending the longevity of the product. In the case of PPGI, when the zinc coating deteriorates, the base metal is susceptible to damage. A galvanized PPGI sheet typically lasts approximately 10 to 15 years.

 

Conversely, the aluminum-zinc alloy on PPGL ensures that the aluminum-rich material corrodes gradually, while the zinc-rich portion corrodes preferentially. This confers additional corrosion resistance compared to the zinc coating alone on PPGI. PPGL can endure up to three times longer than PPGI.

 

Appearance Discrepancy:

 

The surface of PPGL will exhibit a smoother appearance compared to PPGI. This is because aluminum possesses superior adhesion properties compared to zinc. Consequently, PPGL may not necessitate the same pretreatment for painting as galvanized steel sheets do.

Galvalume steel coil

 

Heat Tolerance and Erosion:

 

PPGL demonstrates superior heat resistance compared to PPGI, capable of withstanding temperatures up to 315°C. Additionally, the dense layer of aluminum in PPGL enhances its corrosion resistance, providing further protection against erosion for the base metal. However, the cut edge of PPGL is less shielded due to the honeycomb structure of the coating, which does not adequately protect exposed edges. To mitigate this, a coating can be applied to these edges for additional protection.

 

Applications for PPGI and PPGL:

 

PPGI and PPGL find applications in diverse roofing and wall paneling projects. However, due to its superior corrosion resistance, PPGL is particularly well-suited for harsh outdoor environments like coastal areas exposed to seawater. Additionally, PPGL's excellent heat resistance makes it a preferred material for ovens and chimney pipes.

 

Difference in Price:

 

PPGL generally commands a slightly higher price than PPGI, attributed to its enhanced performance capabilities and fewer manufacturers in the market.

 

Conclusion

 

In summary, while both PPGI and PPGL steel sheets offer excellent performance and durability, their differences in composition, appearance, heat resistance, and corrosion resistance make each type suitable for specific applications. Understanding these differences is essential for selecting the right material for construction and industrial projects.

 

For inquiries about PPGI and PPGL steel sheets, or to find a reliable supplier for your project needs, feel free to contact us. We are committed to providing high-quality steel products and exceptional customer service to meet your requirements.