PPGL Roofing Panel AZ275: The Ultimate Barrier for High-Corrosivity Environments
Our AZ275 Heavy-Coated PPGL Roofing Panels represent the highest tier of protective steel technology, engineered for infrastructure that demands uncompromising durability. While standard panels feature much lighter coatings, this premium grade utilizes a 55% Al-Zn alloy substrate at $275g/m^2$, providing a formidable shield against atmospheric oxidation, chemical exposure, and saltwater spray. Compliant with ASTM A792 and EN 10346,
Bomis Steel’s AZ275 panels are the definitive solution for industrial roofing and coastal cladding where long-term structural integrity is non-negotiable.
Superior AZ275 Substrate: Engineered for LongevityThe $275g/m^2$ Al-Zn coating mass is what sets this product apart in the international market.
This heavy-duty substrate offers:Exceptional Barrier Protection: The high aluminum content ($55\%$) forms a dense, passivated film that slows down corrosion significantly more effectively than standard zinc coatings.Extended Service Life: Designed to endure 25 to 40 years of exposure, AZ275 provides the thickest alloy protection available, drastically reducing maintenance cycles and total cost of ownership.Thermal Reflectivity: The silver-based alloy reflects up to
Applications in Severe Conditions
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Marine & Coastal Infrastructure: Resists salt-induced corrosion in areas within 1km of the shoreline.
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Industrial & Chemical Plants: Withstands sulfur dioxide and other aggressive airborne contaminants better than standard PPGI.
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Agricultural Silos & High-Humidity Warehousing: Provides the necessary thickness to prevent moisture-driven rust in livestock or storage facilities.
Technical Specifications Summary
| Feature | ASTM A792 / EN 10346 Requirement | Bomis Steel Performance |
| Coating Mass | AZ275 ($275g/m^2$) | High-Precision Triple Spot Control |
| Base Metal Grade | SS Grade 33-80 / DX51D+AZ | Full Structural Range Available |
| Paint Type | PVDF / HDP / SMP | High UV Resistance (RUV4) |
| Corrosivity Category | Rated for C4 & C5 Environments | Maximum Protection |
| T-Bend Test | $\leq$ 2T (No Cracking) | Guaranteed Forming Integrity |
Product and specifications
project | Parameter range | Remark |
substrate | Hot-dip aluminum-zinc (AZ) coating | Complies with GB/T 2518 standard |
thickness | 0.12-0.8 mm(±0.02 mm) | Roofing materials commonly used are 0.3-0.6 mm thick. |
width | 665-1050 mm(±2 mm) | Common sizes: 914/1000/1200 mm |
Coating weight | Aluminum-zinc coated steel: 40-150 g/m²; Galvanized steel: 40-275 g/m² | The roofing material commonly used is AZ 50-100 g/m². |
Coating structure | Primer: 5 μm; Topcoat: 7-25 μm; Backcoat: 7-15 μm | The topcoat can be selected from PE/SMP/HDP/PVDF |
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Frequently Asked Questions
1. Why is AZ275 ($275g/m^2$) considered the premium choice for PPGL?
The AZ275 designation signifies a heavy-duty coating mass of $275g/m^2$ of Aluminum-Zinc alloy. Compared to standard AZ50 or AZ150 panels, AZ275 provides a significantly thicker protective layer. According to ASTM A792, this specific thickness is engineered to withstand the most aggressive atmospheric conditions, offering up to 40 years of service life in industrial or coastal environments where standard steel would quickly fail.
2. Can AZ275 PPGL panels withstand high-salt marine environments?
Yes. Our AZ275 PPGL is specifically designed for C4 and C5 (Marine/Industrial) corrosivity categories. The combination of a $55\%$ Aluminum-Zinc substrate and a high-build PVDF paint system ensures the panels resist salt-air corrosion and pitting. It is the gold standard for structures built within 1km of the shoreline or in heavy industrial zones with high sulfur dioxide levels.
3. What is the difference between AZ275 and G90 galvanized steel?
While G90 is a heavy zinc coating ($275g/m^2$ of pure Zinc), AZ275 is a heavy Aluminum-Zinc alloy coating. Under ASTM standards, Al-Zn alloy (Galvalume) provides better barrier protection (thanks to the aluminum) and better heat reflectivity than pure zinc. In most exterior roofing applications, an AZ275 panel will significantly outlast a G90 galvanized panel in terms of both structural integrity and color retention.
4. Does the thick AZ275 coating affect the panel’s formability?
Not at all. Despite the heavy coating mass, our AZ275 PPGL utilizes advanced annealing and continuous hot-dip technology to ensure the alloy remains ductile. The panels pass the 0T-2T bend test, meaning they can be roll-formed into deep corrugated or trapezoidal profiles without any micro-cracking or delamination of the protective layers.
5. What paint system is best paired with an AZ275 substrate?
To maximize the investment in a heavy AZ275 substrate, we strongly recommend PVDF (Polyvinylidene Fluoride) or HDP (High-Durability Polyester) coatings. These paint systems offer the highest UV resistance (RUV4) and chemical stability, ensuring that the aesthetic finish of your roof lasts as long as the heavy-duty Al-Zn protection underneath.





