Aluminum alloy doors and windows surface treatment technology analysis

wood grain thermal transfer, spray color and fluorocarbon color principle and difference

The durability and aesthetics of aluminum alloy doors and windows depend largely on the surface treatment process. Currently on the market the mainstream wood grain thermal transfer, spray color and fluorocarbon color three kinds of technology, there are significant differences in the principle, performance and applicable scenes. This article will analyze the core principles of these three processes, and help consumers make rational choices through comparison.

I.Wood grain heat transfer process: the natural aesthetics of the fake and real

Principle:  
Through high-temperature transfer technology, the special transfer film with wood grain pattern is hot-pressed onto the surface of aluminum profile at 180-220℃. The core of the process lies in the “gas-phase penetration” process: the heat sublimation ink vaporizes at high temperature, penetrates the powder coating and combines with the aluminum substrate to form a permanent texture.

Process flow:  
Aluminum pre-treatment → powder primer coating (weathering layer) → heating of the film (pattern transfer) → cooling and shaping → protective film coating.

Technical Advantage:  
- Realize the perfect combination of solid wood texture and metal performance.  
- Strong three-dimensional texture, close to the real wood.  
- Scratch resistance is better than ordinary spraying (Mohs hardness up to 2H).  
- Environmentally friendly, no solvent emission (VOC emission close to zero).

Limitations:  
- Prolonged exposure to sunlight may produce a slight discoloration (UV resistance of about 2000 hours)  
- Complex curved surfaces are susceptible to texture misalignment.  
- Color choices are limited by the types of woodgrain films available.

Typical applications: new Chinese villas, rustic style home decoration, antique commercial buildings

II.the spray color process: a cost-effective basic solution

Technical classification:  
1. liquid spraying: acrylic/polyester paint spraying by compressed air atomization  
2. powder coating: electrostatic adsorption thermosetting powder coating (180 ℃ curing)

Process Essentials:  
- Six pre-treatment processes (degreasing → washing → chroming → pure water washing)  
- Film thickness control (powder coating 60-80μm, liquid coating 30-50μm)  
- Color difference control need to maintain ΔE ≤ 1.5 (visual no obvious difference)

Performance characteristics:  
- Cost reduction of 40%-60% compared with fluorocarbon spraying  
- Color retention period of 5-8 years under normal environment (reduced to 3-5 years in coastal areas)  
- Weak chemical corrosion resistance (easy to flake off the coating outside the range of pH2-12)

Innovative Improvement:  
- Add nano SiO₂ to improve the surface hardness (up to 4H)  
- UV light curing technology to shorten the processing cycle  
- Metal powder mixing to realize imitation plating effect

III. Fluorocarbon Color Process: The Ultimate Protection for Extreme Environments

Material properties:  
Based on PVDF (polyvinylidene fluoride) resin, the fluorocarbon bonding energy is as high as 485kJ/mol, with super chemical stability. Conventional ratio is 70% PVDF + 30% acrylic resin.

Process standard:  
- Three coats and two baking processes (primer 15μm + top coat 25μm + varnish 10μm)  
- Curing temperature should be strictly controlled at 230±5℃.  
- Passed 4000 hours salt spray test (ASTM B117 standard).

Performance Advantage:  
- Weathering resistance of more than 25 years (light retention rate > 90%)  
- Self-cleaning function (contact angle > 110 °, up to the superhydrophobic standard)  
- Extreme temperature adaptability (-50℃~80℃ stable performance)
Cost considerations:  
- Raw material costs are 3-5 times higher than ordinary spraying.  
- Specialized spraying equipment and exhaust gas treatment systems are required.  
- Processing energy consumption increases by about 40%.

Typical applications: high-rise building curtain walls, coastal areas, chemical parks.
Above, is yooan's analysis and explanation of the surface treatment process of aluminum alloy doors and windows, is it helpful to you?
The next issue, we will take you to analyze the difference between the three kinds of surface treatment process and choose to use, look forward to it together!