In the era dominated by RGB lighting effects and minimalist aesthetics, white CPU coolers have become the top choice for MOD enthusiasts due to their pure texture. However, according to a 2024 consumer survey by PC World, 68% of white cooler users experienced varying degrees of yellowing after 18 months of use, with 23% of cases severely affecting the appearance. This means that one in every four white computer builds faces the risk of "losing its aesthetic appeal."
Ultraviolet Aging: The UV-A (320-400nm) band in the light passing through transparent case panels or ambient light can cause the polymer chains in the coating to break. Test data shows that the yellowing speed of coolers exposed to sunlight for 8 hours a day is 3.2 times faster than those in light - shielded environments.
High-Temperature Oxidation: When the CPU is overclocked, the surface temperature of the cooler can reach 65 - 80°C, accelerating the decomposition of organic pigments in the coating. In a certain brand's white air cooler, under long-term 5.0GHz overclocking, the yellowing index (ΔY) increased from 0 to 15 within 12 months (the industrial standard critical value is 10).
Chemical Corrosion: Sulfates in case dust and fatty acids remaining from sweat can react with the coating through acid-base reactions. In salt spray tests, coatings without anti-corrosion treatment showed punctate discoloration within 72 hours under a 5% sodium chloride solution spray.
Different from visual pollution, coating aging leads to a decrease in thermal conductivity. In a white cooler with ordinary baking paint, the thermal resistance in severely yellowed areas increased by 9% compared to the new product, which is equivalent to a 2.3°C rise in CPU temperature. This is because the micro-cracks inside the coating hinder the heat transfer to the fins, creating local heat dissipation blind spots.
Material: Single-component acrylic resin paint
Process: Single spraying + low-temperature curing at 120°C
Salt Spray Test: Rust spots appear after 200 hours, yellowing ΔY ≥ 8/year
Fatal Flaw: The coating thickness is only 30 - 40μm, with weak UV resistance. Commonly found in entry-level models priced under 100 yuan.
Material: Epoxy resin primer (50μm) + polyimide topcoat (30μm)
Process: Double spraying + high-temperature curing at 180°C, containing 0.5% nano-titanium dioxide UV-resistant particles
Salt Spray Test: No corrosion after 500 hours, yellowing ΔY ≤ 3/year
Technical Advantage: The primer enhances metal adhesion, and the topcoat forms a light shielding layer. The measured weather resistance is increased by 4 times.
Material: Zirconia-based ceramic coating (20μm)
Process: CVD chemical vapor deposition, forming a dense crystal structure
Salt Spray Test: No change after 1000 hours, yellowing ΔY ≤ 1.5/year
Peak Performance: The hardness reaches 5H level, and the thermal conductivity loss is controlled within 5%. However, the cost is 30% higher than that of ordinary coatings.
| Test Items | Ordinary Baking Paint (Brand A) | Dual-Coating Process (GAMEMAX) | Nano-Ceramic (Noctua) |
|---|---|---|---|
| Surface Corrosion Degree | Dense rust spots | No visible changes | Mirror-like appearance |
| Yellowing Index ΔY | 12.7 | 2.8 | 1.2 |
| Thermal Resistance Change Rate | +15% | +3% | +1.5% |
| Coating Adhesion (Cross Hatch Test) | 3B | 5B | 5B |
Test conditions: NSS neutral salt spray chamber, 35°C, 5% NaCl solution, continuous spraying for 500 hours
Essential Indicators: Check whether it has passed the ISO 105-A02 weather resistance test (≥ level 5) and the ASTM B117 salt spray test (≥ 500 hours)
Pitfall Avoidance Guide: Be wary of vague claims such as "nano-coating" and "anti-yellowing." Request third-party test reports from brands. For example, all white coolers from GAMEMAX come with SGS-certified 500-hour salt spray test qualification certificates.
Fin Edge Treatment: Choose models with a folded edge of ≥1mm and rounded corners (such as the Thermalright AXP-90 White) to prevent coating cracking due to stress concentration at right angles.
Heat Pipe Coloring Process: Give priority to heat pipes with the same coating material as the fins. For example, the nano-ceramic heat pipes of the Sigma 550 White have a 98% consistency with the fin coating, avoiding galvanic corrosion between different materials.
High-Humidity Environments: Opt for closed fans with an IP5X dustproof rating or above (such as the Corsair ML120 White) to reduce salt spray intrusion.
Frequent Disassembly and Assembly Users: Choose models with soft rubber wrapping at the contact points between the mounting brackets and the coating (such as the ID-COOLING SE-224 XT White) to avoid metal friction damage to the coating.
Contact Area Isolation: Paste Teflon tape (0.1mm thick) at the contact points between the mounting brackets and the cooler, which can reduce friction damage by 80%.
Thermal Paste Selection: Use transparent or white thermal paste (such as the Shin-Etsu 7921 White version) to avoid gray thermal paste overflowing and contaminating the coating. Apply an amount covering 70% of the CPU cover area.
Cleaning Cycle: Clean the fins with a compressed air gun at an air pressure ≤ 0.4MPa every quarter (blow parallel at a distance of 10cm), and clean with deionized water and a soft brush once a year (do not use alcohol or chlorine-containing cleaners).
Environmental Control: Keep the case away from direct sunlight, and control the humidity between 40% - 60%. An electronic dehumidifier (such as the RUIMA E-2000) can be used to stabilize the humidity at 50%.
For mild yellowing (ΔY ≤ 5), automotive-grade white polishing agents (such as 3M 05954) can be used with a woolen wheel for low-speed polishing, with a restoration rate of up to 70%. For severe yellowing (ΔY > 10), it is recommended to replace the cooler, as coating aging has affected the heat dissipation efficiency.
In 2025, silica aerogel coatings are set to enter mass production. Through their nano-porous structure, these coatings can isolate ultraviolet rays and oxygen. Laboratory data shows that their weather resistance lifespan exceeds 10 years, with a yellowing ΔY ≤ 0.5/year. At the same time, bio-based coatings (such as chitosan-modified coatings extracted from shrimp shells) are beginning to enter commercial use, achieving a dual breakthrough in environmental protection and anti-yellowing performance.
