Colour Painted Aluminium Coil 3003 3105
Colour Painted Aluminium Coil in alloys 3003 and 3105 is widely used for architectural cladding, roofing, ceiling, facades, gutters, and interior decoration where lightweight, corrosion resistance, and colour stability are critical.
Both 3003 and 3105 are non-heat-treatable, manganese-based aluminium alloys with excellent formability and good corrosion resistance. They are ideal substrates for coil coating (pre‑painting) processes.
Alloy Positioning
- 3003: General-purpose Mn alloy with higher strength than 1100; very good workability.
- 3105: Similar to 3003 but with small additions (e.g., Mg) to improve strength and hardness slightly; very common in building cladding and roofing.
2. Typical Chemical Composition
Note: Values below are typical ranges, not guaranteed limits. Product is supplied according to customer-specified standards (e.g., EN, ASTM, GB/T).
Table 1 – Typical Chemical Composition (wt%)
| Alloy | Si (%) | Fe (%) | Cu (%) | Mn (%) | Mg (%) | Zn (%) | Ti (%) | Others (each, %) | Others (total, %) | Al (balance) |
|---|---|---|---|---|---|---|---|---|---|---|
| 3003 | ≤ 0.60 | ≤ 0.70 | 0.05–0.20 | 1.0–1.5 | – | ≤ 0.10 | – | ≤ 0.05 | ≤ 0.15 | Remainder |
| 3105 | ≤ 0.60 | ≤ 0.70 | ≤ 0.30 | 0.30–0.80 | 0.20–0.80 | ≤ 0.40 | ≤ 0.10 | ≤ 0.05 | ≤ 0.15 | Remainder |
- Manganese (Mn) improves strength and corrosion resistance.
- Magnesium (Mg) in 3105 provides slightly higher strength than 3003.
- Low Cu keeps corrosion resistance suitable for outdoor exposure.
3. Product Structure: Coil + Coating System
A colour painted aluminium coil is a multilayer system:
- Aluminium substrate (3003 or 3105, usually in H24, H26, H28 tempers).
- Chromate or environmentally compliant pretreatment to enhance adhesion and corrosion resistance.
- Primer coating (polyester or epoxy-based).
- Topcoat (PE, HDPE, PVDF, or other system, depending on application).
- Backcoat (service or wash coat) for the reverse side.
Table 2 – Typical Coating System Data
| Layer | Type | Typical Dry Film Thickness (µm) | Function |
|---|---|---|---|
| Pretreatment | Chromate / Chrome‑free | 0.5–1.0 | Corrosion protection, adhesion |
| Primer | Polyester / Epoxy | 5–10 | Adhesion, corrosion barrier |
| Topcoat | PE / HDPE / PVDF | 15–25 (PE), 20–28 (PVDF) | Colour, UV resistance, durability |
| Backcoat | Epoxy / Polyester | 5–10 | Protection of rear side, bonding layer |
4. Features & Performance
4.1 Mechanical Properties of Substrate (Typical)
Values below are indicative for common tempers. Actual values depend on temper, thickness, and standard.
Table 3 – Typical Mechanical Properties
| Alloy | Temper | Tensile Strength Rm (MPa) | Yield Strength Rp0.2 (MPa) | Elongation A50 (%) | Notes |
|---|---|---|---|---|---|
| 3003 | H14/H24 | 130–185 | 115–160 | 2–8 | Balance of strength / form. |
| 3003 | H26/H28 | 165–215 | 150–190 | 1–6 | Higher strength, less ductile |
| 3105 | H14/H24 | 145–200 | 120–170 | 2–8 | Slightly higher strength |
| 3105 | H26/H28 | 170–230 | 150–200 | 1–5 | For stiff panels, roofing |
4.2 Coating Performance Metrics
Typical test results for quality coil-coated products:
Table 4 – Coating Performance (Typical Values)
| Property | Test Method (Ref.) | Typical Value / Result |
|---|---|---|
| Pencil hardness (topcoat) | ASTM D3363 | HB–2H (PE), H–2H (PVDF) |
| Adhesion (cross‑cut) | ISO 2409 / ASTM D3359 | Grade 0 (no flaking) |
| Impact resistance | ASTM D2794 | ≥ 9–10 J (no cracking) |
| T‑bend (formability) | ASTM D4145 | 2T–3T for PE; 2T–4T for PVDF |
| Gloss (60°) | ASTM D523 | 20–80 GU (customizable) |
| Salt spray resistance | ASTM B117 | 500–1000 h, no base metal cor. |
| UV / colour retention (PVDF) | ASTM G155 | ΔE ≤ 5 after 20+ years (typ.) |
| Boiling water resistance | Internal | No blistering / loss of gloss |
5. Dimensional & Technical Specifications
Table 5 – Standard Dimensional Range
| Parameter | Typical Range | Notes |
|---|---|---|
| Thickness | 0.20–1.50 mm | Special up to ~2.0 mm on request |
| Width | 20–1600 mm | Common: 600–1250 mm for roofing / cladding |
| Coil inner diameter | 405, 505, 508, 610 mm | According to customer line requirements |
| Coil outer diameter | Max. 1500–1600 mm | Limited by handling & transport |
| Coil weight | 2–5 tons (small), 5–8 tons (standard) | Customizable |
| Coating thickness | 18–35 µm (front), 5–10 µm (back) | Depending on system (PE / PVDF etc.) |
| Colour system | RAL, NCS, custom | Solid, metallic, wood‑grain, marble, etc. |
Tolerances (Typical, per EN/ASTM or Mill Standard)
- Thickness tolerance: ±0.02–0.05 mm depending on gauge
- Width tolerance: ±0.5–1.0 mm
- Diagonal difference (sheet cut from coil): ≤ 1.0–1.5 mm/m
6. Advantages of Colour Painted Aluminium Coil 3003/3105
6.1 Lightweight, High Strength-to-Weight Ratio
- Density of aluminium ≈ 2.7 g/cm³, about one-third of steel.
- Reducible structural weight while maintaining panel stiffness, especially when combined with profiles or composite structures.
6.2 Excellent Corrosion Resistance
- Mn-containing alloys 3003 and 3105 have natural protective oxide layers, further enhanced by pretreatment and coating.
- Suitable for urban, industrial, and coastal atmospheres when correct coating system (e.g., PVDF) is selected.
6.3 Stable Colour & Aesthetic Flexibility
- Wide colour and gloss range: matte, satin, high gloss, metallic, and patterned finishes.
- PVDF systems deliver long-term colour stability and chalk resistance for high-end architectural façades.
- Uniform factory-applied coating eliminates on-site painting variability.
6.4 Processing & Formability
- Suitable for:
- Roll forming
- Bending, hemming
- Punching, slitting, shearing
- Deep drawing for certain products (with suitable temper and bend radius)
- Good formability reduces risk of cracking or orange peel when conventional press and roll forming parameters are respected.
6.5 Sustainability
- Aluminium is fully recyclable without loss of properties.
- Coil coating is an efficient, controlled process with optimized paint usage and low environmental footprint per square metre of finished surface.
7. Main Applications
Colour Painted Aluminium Coil 3003/3105 is used across construction, transportation, and interior finishing.
7.1 Building & Construction
| Application | Requirements | Recommended Alloy / Coating |
|---|---|---|
| Roofing sheets & tiles | Weather resistance, formability | 3105 H24/H26, PE or PVDF |
| Wall cladding & façade panels | Long-term colour stability, flatness | 3003 or 3105 H24, PVDF topcoat |
| Rain gutters & downpipes | Corrosion resistance, bendability | 3105 H24, PE or HDPE |
| Soffits & ceiling panels | Decorative, light weight, cleanability | 3003 H14/H24, PE |
| Roller shutters & doors | Abrasion, impact resistance | 3105 H26/H28, HDPE or modified PE |
| Sandwich / composite panels | Bond strength, flatness | 3003/3105 H16/H18 for ACP skin |
7.2 Interior & Industrial Uses
- Decorative ceiling strips, ventilation ducts
- Appliance panels and trims
- Signboards, advertising boards
- Furniture profiles, fixture covers
For interior projects where UV is limited, standard polyester (PE) coatings often provide sufficient performance at lower cost.
8. Selection Guide: 3003 vs 3105
| Requirement / Condition | Better Choice | Reason |
|---|---|---|
| Maximum formability (deep forming, tight bends) | 3003 | Slightly softer, easier forming in same temper |
| Higher strength for roofing / cladding profiles | 3105 | Mg addition increases yield strength |
| Standard building façade with PVDF | 3003 or 3105 | Both suitable; decision based on cost & stock |
| Gutter, downpipe, accessories | 3105 | Widely used, good strength and corrosion balance |
| Interior ceiling & panels | 3003 | Excellent workability, cost-effective |
9. Handling, Fabrication & Storage Tips
To maintain coating quality:
- Avoid sharp tools or contaminated rollers during processing.
- Maintain adequate bend radius (generally ≥ 1–2 times thickness, depending on coating and temper).
- Store coils:
- In dry, ventilated areas.
- Off the ground on dunnage to avoid condensation.
- With ends protected from mechanical damage.
- Remove protective film (if applied) soon after installation to prevent adhesive transfer or ageing marks.
Colour Painted Aluminium Coil 3003/3105 combines:
- Light weight with adequate structural strength
- Reliable corrosion resistance even in challenging environments
- Excellent aesthetics and colour stability, especially in PVDF systems
- Good formability and processability for a wide range of profiles and panels
- Sustainable, recyclable material for modern building envelopes
By carefully choosing the alloy (3003 or 3105), temper, coating system, and thickness, customers can optimize their design for service life, appearance, and total cost, making these painted coils a highly efficient choice for both exterior and interior applications.
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