3004 H24 PVDF Pre-Painted Aluminium Sheet
3004 H24 PVDF Pre-Painted Aluminium Sheet: A System-Level View From Substrate To Skyline
When architects and fabricators talk about 3004 H24 PVDF pre-painted aluminium sheet, the conversation often stops at color charts and corrosion resistance. Yet the real value of this material only appears when you look at it as a complete engineered system: alloy design, temper, surface chemistry, coating architecture and standards all working together from the mill to the façade or roofing system.
Taking that system-level view reveals why 3004 H24 with PVDF coating has become a go-to choice for long-life building envelopes, signage and high-end cladding in harsh environments.
the “3004 H24” code as a performance recipe
The grade and temper are more than a code on a datasheet. They are essentially a recipe for how the sheet will behave during forming, installation and decades of service.
The 3004 alloy is a manganese-based wrought aluminium from the 3xxx series. It is non-heat-treatable, which means its strength comes from cold working and the solid-solution strengthening of manganese and magnesium, not from solution treatment and artificial ageing like 6xxx or 7xxx alloys.
The H24 temper describes a very specific mechanical history. The sheet is strain-hardened to a level between quarter-hard and half-hard, then partially annealed to achieve controlled strength and ductility. In practical terms, this temper gives a robust yield strength for panel stiffness and wind resistance while preserving enough elongation for roll forming, bending and hemming without cracking either the substrate or the PVDF paint film.
Typical mechanical properties of 3004 H24 pre-painted sheet are commonly in the following ranges, depending on thickness and process route:
Tensile strength: approximately 200–260 MPa
Yield strength (0.2% proof): approximately 140–220 MPa
Elongation (A50): approximately 5–12%
This balance is critical when you are profiling long roofing sheets or cassette façades where localized strain is inevitable. Too soft, and panels oil-can and deform; too hard, and microcracking in the coating becomes a long-term corrosion risk. H24 deliberately sits in the “sweet spot” between these extremes.
Chemical composition: why 3004 behaves the way it does
Viewed from a surface engineering perspective, the chemistry of 3004 is chosen not only for core strength but for predictable interaction with pretreatments and PVDF primers. A representative chemical composition of 3004 alloy is:
| Element | Content (wt. %) |
|---|---|
| Si | ≤ 0.30 |
| Fe | ≤ 0.70 |
| Cu | ≤ 0.25 |
| Mn | 1.0–1.5 |
| Mg | 0.8–1.3 |
| Zn | ≤ 0.25 |
| Ti | ≤ 0.15 |
| Others (each) | ≤ 0.05 |
| Others (total) | ≤ 0.15 |
| Al | Balance |
Each of these ranges has a functional implication.
Manganese is the primary strengthening element; it forms finely dispersed intermetallics that refine the grain structure and increase strength without making the alloy brittle. From a coil-coating viewpoint, this refined structure also leads to a more uniform response during cleaning, alkaline etching and conversion coating.
Magnesium adds moderate solid-solution strengthening and has a subtle influence on corrosion behavior. In controlled proportions, Mg helps maintain good general corrosion resistance, important beneath cut edges and at fasteners where the coating is mechanically compromised.
Low copper content keeps susceptibility to intergranular corrosion down, which is a difference from higher-copper alloys that may not withstand coastal or industrial atmospheres as reliably.
Controlled levels of iron, silicon and zinc minimize unwanted coarse intermetallics that could telegraph through thin coating systems and affect appearance or cause coating holidays.
Looking through a coating engineer’s lens, 3004’s chemistry delivers a stable, predictable oxide layer during pretreatment, which is essential for long-term PVDF adhesion. This is one of the quiet reasons why 3xxx-series pre-painted sheet shows such long lifetimes in real-world exposure tests.
PVDF coating: not just color, but a molecular shield
The PVDF layer on 3004 H24 sheet is not a simple paint; it is a fluoropolymer-based laminate system engineered from the molecule outwards. Polyvinylidene fluoride resins are prized for the carbon–fluorine bond, one of the strongest in organic chemistry. This bond structure resists UV radiation, chemical attack and chalking far better than polyester or standard polyurethane coatings.
A typical PVDF system on 3004 H24 consists of:
A chemically bonded pretreatment or conversion coating tailored to aluminium’s oxide layer
A corrosion-resistant primer that wets the pretreated surface and provides a bridge to the fluoropolymer topcoat
A topcoat with usually 70% PVDF resin content (by weight of resin solids) combined with high-grade pigments
In architectural-grade products, PVDF coatings are usually formulated and tested in line with international benchmarks such as:
AAMA 2605 (for high-performance exterior architectural coatings)
EN 13523 series (for coil-coated metals)
ISO 2810 and ISO 16474 (weathering and UV resistance)
Even when these standards are not explicitly named on a local datasheet, high-end 3004 H24 PVDF products are designed with equivalent performance in mind: color retention over decades, minimal chalking and excellent gloss stability under intense sunlight and acid rain.
dimensional and coating parameters in practice
In real projects, parameters are as important as alloy and coating chemistry because they dictate how the sheet will integrate with system design. Typical specification windows for 3004 H24 PVDF pre-painted sheet are:
Thickness: about 0.20–1.50 mm for coil-coated sheet, with façade and standing seam roofing often in the 0.7–1.2 mm range
Width: commonly 600–1600 mm, depending on rolling mill capability and line design
Coating thickness: PVDF topcoat usually around 20–25 μm on the weather side, primer about 5–7 μm; back coat 5–10 μm, often in a service or primer-only formulation to improve bond in composite panels
Coating hardness, flexibility and adhesion are systematically checked with tests such as T-bend, reverse impact and cross-hatch adhesion according to standards like EN 13523 or ISO 1519. For a façade or roofing engineer, those test values translate directly into confidence that the sheet can be profiled into deep trapezoids, lock-seamed or folded, and then survive years of thermal cycling without failure.
Implementation standards: connecting mill quality with site performance
While alloy composition is governed by standards such as EN 573 and mechanical properties by EN 485 or ASTM B209, pre-painted 3004 H24 sheet inhabits a multi-standard ecosystem. Quality-conscious producers will align their product with:
EN 1396 for coil-coated aluminium
EN 13523 test methods for organic coatings on coil-coated metals
GB/T or ASTM equivalents for regional compliance, for instance ASTM B209 for flat-rolled aluminium and ASTM D-series for coating performance tests
What matters for specifiers is how these standards converge to guarantee:
Consistent substrate thickness and flatness, so panel systems align precisely and avoid oil-canning
Verified coating adhesion, flexibility and abrasion resistance, crucial for formed profiles and transport
Reliably controlled gloss and color tolerances, to prevent visible banding or mismatch across large façades
When backed by robust factory quality systems and traceability, these standards turn 3004 H24 PVDF sheet from a commodity coil into a predictable building system component.
Alloy tempering and coating interaction: a less discussed but critical interface
One of the more subtle technical points is how temper selection and coil-coating process interact. In pre-painted 3004 H24 sheet, the alloy is cold-worked and partially annealed to H24 condition first, then fed through a continuous coil-coating line where the organic coating is cured at elevated temperatures.
Process engineers deliberately design the H24 temper to accommodate this coating bake without drifting the mechanical properties outside target ranges. If the bake is too hot or too long, partial over-annealing could soften the alloy, compromising panel strength and stiffness. If it is too mild, the coating may not fully cure, risking poor chemical resistance and flexibility.
This is a reason many architectural coil coaters specialize in 3xxx and 5xxx alloys: they understand the narrow thermal window in which both substrate temper and coating chemistry are optimized simultaneously. For the end user, the payoff is a sheet that bends cleanly, holds profile shape under load and still delivers full PVDF weathering performance.
From coil to application: where 3004 H24 PVDF excels
Seen through an application engineer’s lens, the real power of 3004 H24 PVDF pre-painted sheet is its versatility combined with predictable durability. Typical use cases include:
Architectural façades and rainscreen cladding, where light weight, formability and stable appearance over decades are crucial
Standing seam and profiled roofing, especially in coastal or high-UV environments where inferior coatings quickly chalk and fade
Ceilings, soffits and interior liners, where color consistency and cleanability matter
Composite panels, where 3004 H24 PVDF coil forms the outer skin bonded to a core, taking advantage of its controlled stiffness and robust coating
The combination of manganese-strengthened core and fluoropolymer outer shield means that design teams can push for more daring geometries and stronger color statements without sacrificing structural integrity or long-term aesthetics.
Looking ahead: why 3004 H24 PVDF remains a strategic choice
From this holistic vantage point, 3004 H24 PVDF pre-painted aluminium sheet is less a raw material and more a tuned, multi-layer system. Alloy chemistry, tempering schedule, surface pretreatment, fluoropolymer coating and compliance with international standards all intersect to deliver a predictable lifecycle.
In an era where total cost of ownership and environmental impact matter as much as initial material price, that predictability translates into fewer repaint cycles, low maintenance and reduced replacement frequency. For fabricators, it means shorter learning curves and fewer surprises on the profiling line. For architects and investors, it means façades and roofs that continue to look intentional long after the scaffolding has come down.
By 3004 H24 PVDF not only as a color choice but as an engineered system from substrate to skyline, it becomes clear why this material continues to anchor high-performance building envelope solutions worldwide.
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