Prepainted Galvanized Steel Coils for Roofing combine the strength of the base metal, the corrosion resistance of the metallic coating, and the weatherability and decorative appeal of the organic finish. They feature a flat surface and diverse color options, offering excellent processability for bending, profiling, and cutting. Widely used in steel structure workshops, roofing and wall cladding, profiled steel sheets, sandwich panels, architectural curtain walls, home appliance casings, storage equipment, and municipal hoarding, they are a mainstream cladding material in the steel structure and construction industries.
1. Substrates primarily fall into two categories: hot-dip galvanized and Al-Zn coated. The metallic coating blocks moisture and delays substrate rusting; combined with the organic surface coating, it provides dual-layer protection, offering corrosion resistance far superior to standard black steel sheets.
2. Performance varies significantly by substrate: galvanized steel offers high cost-effectiveness and is suitable for standard inland environments; Al-Zn coated steel offers superior resistance to fingerprints, acids, alkalis, and high temperatures, making it ideal for highly corrosive areas such as coastal regions and chemical industrial zones.
3. Finished products are pre-painted at the factory with strong paint adhesion, ensuring the coating does not easily peel or flake off; outdoor service life ranges from 8 to 25 years, depending on the coating type.
1. A rich color palette is available, featuring over a hundred standard options such as Ocean Blue, White-Grey, Brick Red, and Ivory White. The surface is smooth, flat, and uniform in color, eliminating the need for on-site repainting.
2. Surface textures include solid colors, wood grain, stone grain, and matte finishes, combining functional cladding with decorative appeal; they are suitable for architectural facades, landscape projects, prefabricated housing, and other applications requiring specific aesthetic styling. Processing and Forming Performance
1. Excellent overall cold-working performance; suitable for shearing, bending, profiling, hemming, and punching. It can be processed into a full range of building envelope components, such as profiled steel sheets, floor decking, trim pieces, and gutters.
2. The coating offers good flexibility; the paint finish resists cracking or peeling during cold bending or seaming of standard-thickness sheets, making it compatible with the entire steel structure envelope fabrication process.
3. Supplied in coil form, allowing for continuous production and high material utilization rates; ideal for large-scale processing.
1. Lightweight and thin, imposing minimal overall load on the main steel structure; offers high efficiency in transportation, hoisting, and on-site installation.
2. Uniform profiles ensure tight overlapping and interlocking between sheets, providing excellent waterproofing, wind resistance, and sealing performance; facilitates convenient installation of complementary envelope components like gutters, trim pieces, and purlins.
3. High degree of standardization; products of the same specification offer strong versatility and interchangeability, simplifying project integration, maintenance, and replacement.
Standard Polyester (PE): Mainstream, general-purpose option with high cost-performance; weather resistance meets the needs of inland factories and indoor envelopes; widest range of applications.
High Durability Polyester (HDP): Strong UV and fade resistance; suitable for outdoor structures and regions with intense sunlight.
Fluorocarbon (PVDF): Superior weather, acid/alkali, and aging resistance; suitable for coastal areas, chemical industrial parks, and high-end architecture; comes at a higher cost.
Silicon-Modified Polyester (SMP): Overall performance falls between PE and HDP, balancing cost-effectiveness with weather resistance.
1. Standard operating temperature range is -20°C to 120°C; avoid prolonged exposure to high temperatures, open flames, or environments with extreme temperature fluctuations.
2. Moderate surface hardness; scratches can easily occur from forceful contact with sharp, hard objects, so protective measures are required during construction and transport.
3. Metal substrates are exposed at weld seams and cut edges; anti-corrosion touch-up paint must be applied later to prevent premature rusting at these points. VII. Cost and Economic Efficiency
With mature mass production and an abundant supply chain, the overall cost is lower than the "steel plate + on-site painting" method. It eliminates on-site painting processes, shortens construction schedules, and reduces labor and environmental compliance costs, delivering outstanding overall economic benefits.
Can be roll-formed into profiled steel sheets for roofing, wall cladding, floor decking, and more. Paired with gutters, trim components, and purlins, these serve as the primary roofing and wall envelope materials for industrial plants, warehouses, and workshops.
Used for exterior walls, roofing, and partition panels in light-gauge steel villas, modular homes, portable cabins, and temporary structures; features high standardization and rapid assembly.
Serves as the top and bottom skins for rock wool or polyurethane sandwich panels used in cleanrooms, cold storage, insulated facilities, and fire-rated compartments, providing enclosure, thermal insulation, and fire resistance.
Roadside hoarding, temporary construction site fencing, bus shelters, guardrail panels, billboards, and landscape structures; offers aesthetic appeal and durability.
Casings for refrigerators, washing machines, air conditioners, and water heaters; cabinets and panels for electrical appliances, equipment chassis, and power distribution units.
Container wall panels, box truck body panels, refrigerated vehicle shells, and protective panels for logistics equipment.
Roofing and wall panels for greenhouses, livestock shelters, agricultural fencing, and storage sheds.
Fabricated into various trim pieces, edge coverings, drip edges, door and window frames, and decorative panels to suit architectural facade designs.
The mainstream market choice; offers excellent cost-performance and corrosion resistance suitable for standard environments. Applications: Standard inland factory buildings, temporary construction hoarding, interior partitions, home appliance casings, and projects in dry environments.
Superior resistance to acids, alkalis, high temperatures, and corrosion; excellent anti-fingerprint properties.
Applications: Coastal regions, chemical plant areas, high-temperature workshops, high-humidity environments, and components exposed to the outdoors for extended periods.
PE offers the best overall cost-performance ratio and is suitable for both indoor and inland outdoor use. Applications: Standard factory buildings, hoarding, home appliances, and simple structures.
SMP offers better fade resistance and weatherability than PE, with a balanced cost-performance ratio. Applications: Standard outdoor factory buildings and general civil architecture.
HDP features strong UV and aging resistance and is highly fade-resistant. Applications: Areas with intense sunlight, large venues, high-end factory buildings, and outdoor facilities.
PVDF offers top-tier weatherability, salt spray resistance, and chemical resistance, ensuring the longest service life. Applications: Coastal areas with severe corrosion risks, chemical industrial parks, landmark buildings, and high-end curtain walls.
1. Steel Structure Engineering: Industrial plants, steel warehouses, large venues, and roofing/wall cladding systems.
2. Construction Engineering: Prefabricated buildings, light-gauge steel villas, insulated housing, and door/window/facade decoration.
3. Municipal Engineering: Roadside hoarding, traffic facilities, outdoor advertising, and landscape projects.
4. Home Appliances & Hardware: Casings for household and commercial appliances, power distribution cabinets, and equipment enclosures.
5. Transportation: Shipping containers, specialized vehicles, bus interiors, and logistics equipment.
6. Agricultural Greenhouses: Greenhouses, livestock shelters, and agricultural enclosures. Key Specifications
Substrate thickness (excluding coating): 0.20–2.0 mm; common sizes: 0.4/0.5/0.6/0.8/1.0 mm
Width: 600–2000 mm; common sizes: 1000/1200/1250/1500 mm
Coil inner diameter: φ450/508/610 mm
Coil weight: 3–15 tons/coil
1. Substrate types
Hot-dip galvanized (GI/PPGI): Mainstream choice; high cost-performance ratio
Aluzinc/Galvalume (GL/PPGL): 55% Al + 43.4% Zn + 1.6% Si; corrosion resistance is 2–3 times that of galvanized steel
Cold-rolled substrate: For indoor use or temporary enclosures only
2. Coating weight (double-sided, g/m²)
Hot-dip galvanized (GI): 80/120/180/275; ≥180 for exterior architectural use
Aluzinc (GL): 100/150; ≥150 for highly corrosive environments
1. Structure (from outside to inside)
Topcoat: 15–25 μm (weather resistance, aesthetics)
Primer: 5–8 μm (adhesion, secondary corrosion protection)
Back coat: 5–10 μm (moisture resistance, corrosion protection)
Chemical conversion layer: 2–5 μm (bonding substrate to coating)
2. Common coatings and typical film thicknesses
PE (Standard Polyester): Topcoat ≥20 μm; indoor/inland use; 5–8 years
SMP (Silicon-Modified Polyester): Topcoat ≥20 μm; urban/general outdoor use; 10–15 years
HDP (High-Durability Polyester): Topcoat ≥25 μm μm; intense sunlight / industrial environments, 15–20 years
PVDF Fluorocarbon: Topcoat ≥23 μm; coastal / chemical / high-end applications, 20–25 years
Yield Strength (Rp0.2): 220–350 MPa
Tensile Strength (Rm): 300–450 MPa
Elongation (A80): ≥20% (thickness ≤0.7 mm); ≥22% (thickness > 0.7 mm)
Hardness: HRB 50–70
Cold Bending: 180° without cracking (T-bend: T≤2)
1. Adhesion
Cross-hatch: Grade 0 (no paint detachment)
Impact: ≥60 cm·kg (no cracking or detachment under direct/reverse impact)
Cupping: ≥6 mm (no coating cracking)
2. Corrosion Resistance (Salt Spray Test)
PE: ≥500 h (neutral salt spray; no red rust at scratch ≤1 mm)
SMP: ≥750 h
HDP: ≥1000 h
PVDF: ≥2000 h
3. Weather Resistance (QUV Aging)
PE: ≥1000 h (ΔE≤5, no chalking)
HDP: ≥3000 h
PVDF: ≥5000 h
Temperature Range: -20°C to 120°C; short-term peak ≤150°C
Processing: Shearing, bending, profiling, hemming, and punching; R≥1.5t (t ...to prevent cracking (based on sheet thickness)
Cut-edge protection: Exposed cross-sections require touch-up anti-corrosion paint
Storage: Dry and ventilated; protect from direct sunlight and rain; store flat; keep moisture-proof
PPGI-Z80-PE-0.5×1250: Hot-dip galvanized (80g/m²), PE coating, 0.5mm × 1250mm
PPGL-AZ150-PVDF-0.6×1000: Al-Zn alloy coated (150g/m²), PVDF (fluorocarbon) coating, 0.6mm × 1000mm
Inland industrial plants: PE + Galvanized (120g)
Coastal / Chemical plants: PVDF + Al-Zn alloy coated (150g)
High sun exposure: HDP + Galvanized (180g)
Indoor / Home appliances: PE + Galvanized (80g)
1.Green & Low-carbon: Widespread adoption of water-based/high-solid coatings (VOC ≤ 120g/m²); recycled substrates account for >20%; zero-carbon production lines achieve emissions as low as 0.29 tonnes CO₂/tonne.
2.High-end Functionalization: PVDF/HDP coatings account for 27.4%; surge in self-cleaning, antibacterial, thermal insulation, and fire-retardant coatings; growing demand for high-strength, ultra-thin sheets (<0.3mm).
3.Intelligent Manufacturing: AI quality inspection accuracy reaches 98%; product changeover time ≤ 45 minutes; full-process management via digital twins.
4.Industry Consolidation: CR10 rises to >55%; industry leaders establish a closed-loop "Steelmaking — Cold Rolling — Color Coating" system.
5.Demand Differentiation: Stable demand in construction; explosive growth in new energy (PV/energy storage growing >30% annually); home appliance upgrades; lightweighting in transportation.
Address
Tianjin International Metal Logistics Park, Jinan Economic Development Zone (East Zone), Jinan District, Tianjin, China
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