3003 3004 3005 Durable Color Coated Aluminum Coil Roll For Gutter Coil

This is the primary reason why colored-coated aluminum is used for downspouts.

• Natural corrosion resistance of aluminum: When aluminum metal is exposed to air, it reacts rapidly with oxygen to form a dense and stable oxide aluminum passivation film. This film effectively prevents the internal metal from further contact with water and oxygen, providing long-term protection. This is fundamentally different from steel, which relies on a galvanized layer to protect the anode and prevent corrosion.
• Dual protection of the coating: The color-coated process provides the aluminum material with a dual protection mechanism (Dual Protection System): ① Physical barrier: The coating (such as PE or PVDF) itself is a dense polymer film that completely isolates the aluminum substrate from water, acid rain, and pollutants outside. ② Chemical inertness: High-quality coatings have extremely strong resistance to chemical corrosion and can resist the acidic substances dissolved in rainwater and the degradation caused by ultraviolet (UV) rays.
• Alloy selection: The aluminum used for gutter coils is usually manganese-based alloys such as 3003, 3004, or 3005. These alloys have good formability while maintaining the excellent corrosion resistance of pure aluminum, making them particularly suitable for downspouts that are exposed to humid environments for a long time.

2. Surface Treatment&Aesthetics

Downspouts are an important visual component of the building facade and need to match the style of the roof and exterior walls.

• Abundant color options: The color coating process at YONGSHENG factory can provide any RAL color range, as well as special effects such as wood-grain imitation and stone imitation. This offers architects and owners great design flexibility, ensuring that the downspouts can seamlessly blend with the overall style of the building and become a decorative line rather than a simple functional component.
• Long-lasting color: High-performance coatings (especially PVDF) have strong resistance to ultraviolet rays, effectively resisting the flaking and fading caused by sunlight exposure. This means that after ten or twenty years, the color of the downspouts will still remain bright, maintaining the overall aesthetic of the building.
• Consistent coating quality: The roller coating process at YONGSHENG factory is completed on highly automated production lines, ensuring uniform coating thickness and consistent color, avoiding problems such as run-off and color differences that may occur during later spraying.

The downpipe needs to undergo roll forming to take on a specific shape, and this process has specific requirements for the material's mechanical properties.

• Excellent formability: Aluminum metal itself has good ductility. Alloys such as 3003 and 3005, when in the appropriate tempering state (such as H14 and H24), possess sufficient strength and excellent machinability, and can be rapidly and continuously bent into complex cross-sectional shapes on the rolling production line without cracking.
• Strength-to-weight ratio: The density of aluminum is approximately one-third that of steel. This means that the painted aluminum downspouts are very lightweight. This characteristic brings multiple benefits: ① Installation is convenient: A single person can easily carry and install longer pipe sections, reducing labor intensity and installation costs. ② Low structural load: The load requirements for eaves and suspension systems are low, especially suitable for light wooden structures or renovation of old buildings.
• Flexibility: Aluminum has a certain elasticity and can withstand slight collisions or thermal expansion and contraction, and is not prone to permanent deformation.

4. Service Life & Life-Cycle Cost

This is the most competitive economic advantage of the color-coated aluminum downspout.

• Extremely long service life: A high-quality coated aluminum downspout system (such as one with PVDF coating) can have a service life of over 40 years in normal conditions and requires no maintenance. This is far longer than galvanized steel (even if painted, it is prone to rusting from the cut edges) and PVC materials (which tend to age and become brittle).
• Low total life cycle cost: Although its initial purchase cost may be higher than PVC or ordinary galvanized steel, due to its almost zero maintenance cost (no painting, no replacement) and extremely long service life, in terms of its entire usage period, the total cost is the lowest. This is a typical "invest in the initial stage, save in the future" high-value and cost-effective choice.

5. Environmental Sustainability

Modern buildings are increasingly emphasizing the environmental attributes of materials.

• Recyclability: Aluminum is a 100% infinitely recyclable metal, and the energy required for recycling and remelting is only 5% of that needed for producing new aluminum. The recycled color-coated aluminum downspouts have extremely high recycling value and are a typical green building material.
• No pollutant emissions: The rainwater flowing from the aluminum downspouts is not contaminated (in contrast, the initial outflow of rainwater from copper downspouts may contain trace amounts of copper ions, which are harmful to certain aquatic organisms).