How well do aluminum FFU air supply units perform in terms of corrosion resistance?
Publish Time: 2025-11-05
In environments with extremely high air cleanliness requirements, such as cleanrooms, laboratories, hospital operating rooms, and precision electronics manufacturing, the long-term stable operation of FFUs is crucial as the core equipment for air circulation and purification. Aluminum FFU air supply units are widely used due to their lightweight, high strength, and excellent structural stability. The corrosion resistance of the aluminum casing directly affects the service life and cleanliness assurance capability of the equipment in harsh environments such as humidity, chemical gases, or high salt spray.
1. Intrinsic Properties of Aluminum: Natural Oxide Film Provides Basic Protection
Aluminum is a reactive metal, but it reacts rapidly with oxygen in the air to form a dense, stable aluminum oxide passivation film, typically 2–10 nanometers thick. This natural oxide film has good chemical inertness, effectively isolating water vapor, oxygen, and other corrosive media from contact with the base metal, thus significantly delaying further corrosion. Compared to easily rusting materials like carbon steel, aluminum almost never develops "red rust" in normal indoor environments, maintaining a clean and bright surface. This is crucial for maintaining a cleanroom environment free of particle shedding.
To cope with more demanding operating conditions, aluminum FFU shells commonly undergo anodizing. This process uses electrochemical methods to generate an artificial oxide film on the aluminum surface, with a thickness of 10–25 micrometers. This film has high hardness, controllable porosity, and can be sealed to completely close micropores, greatly improving corrosion resistance, wear resistance, and contamination resistance. Anodized aluminum shells can withstand over 500 hours of neutral salt spray testing without significant corrosion, fully meeting the material durability requirements of cleanroom standards such as GMP and ISO 14644.
3. Structural Design Advantages: Avoiding Water Accumulation and Galvanic Corrosion Risks
Aluminum FFU shells typically employ integrated bending or seamless welding processes, resulting in a smooth surface without dead corners and tightly sealed seams, effectively preventing the accumulation of condensate or cleaning fluid. Meanwhile, aluminum has a low density and high thermal conductivity, making it less prone to condensation in environments with varying temperature and humidity, thus structurally reducing the risk of corrosion. Furthermore, in system integration, if connections to other metals are required, insulating gaskets or coatings can be used to prevent galvanic corrosion caused by potential differences, further ensuring long-term reliability.
4. Comparative Advantages: Lightweight and Corrosion-Resistant, Superior to Traditional Galvanized Steel Sheets
Compared to traditional galvanized steel FFU shells, the aluminum solution, while having a slightly higher initial cost, offers significant advantages in corrosion resistance: galvanized layers are prone to "white rust" in humid or acidic environments, affecting aesthetics and potentially peeling off and contaminating the cleanroom environment; while aluminum, even after long-term use, may only show slight, uniform oxidation, with no risk of peeling, better meeting the core requirement of "zero particulate release" in cleanrooms. At the same time, aluminum weighs only 1/3 of steel, facilitating installation and maintenance and reducing the load on the ceiling.
5. Application Scenario Verification: Widely Used in High-Requirement Clean Environments
Currently, aluminum FFUs are widely used in high-end semiconductor plants, biosafety laboratories, pharmaceutical workshops, and hospital clean operating rooms. These environments often involve frequent disinfection, high humidity control, or cleanliness levels exceeding ISO Class 5, placing extremely stringent requirements on material corrosion resistance and cleanliness performance. The long-term stable performance of aluminum casings in these scenarios fully verifies their superior corrosion resistance and reliability.
The aluminum casing of aluminum FFU air supply units, with its self-protective natural oxide film, enhanced protection through anodizing, rational structural design, and lightweight and clean comprehensive advantages, exhibits superior corrosion resistance far exceeding that of traditional metal materials. It not only ensures the long-term stable operation of FFUs in complex environments but also safeguards the air quality and process safety of clean spaces, making it an indispensable and reliable choice in modern high-end cleanroom engineering.
