1.What are the core factors affecting fade resistance?
Pigment type: Inorganic pigments have strong chemical stability and are much more resistant to fading than organic pigments;
Resin weather resistance: Resins such as fluorocarbon and high-weather-resistant polyester have better pigment encapsulation and anti-aging properties, which can reduce pigment loss;
Additive addition: Antioxidants and ultraviolet absorbers added to the coating can delay pigment oxidation and reduce fading.
2.What is the accelerated aging test method?
Xenon lamp aging test: simulates the full spectrum of sunlight, controls temperature, humidity and spray cycle, and simulates outdoor rain and dew erosion. The test standard refers to ISO 11341, ASTM G155 or GB/T 1865, and the test duration is usually 500-3000 hours.
UV aging test: uses fluorescent UV lamps, focusing on the damage of UV rays to pigments.
3.What are the assessment considerations in practical applications?
Matching of test conditions:
The light intensity and humidity in different regions vary greatly. It is necessary to adjust the accelerated test parameters according to the use environment to avoid the test results being out of touch with reality.
Batch stability:
Different production batches of the same model of color-coated coils may have different anti-fading properties due to pigment ratios and process fluctuations. It is necessary to sample and test multiple batches of samples.
Comprehensive performance correlation:
Fading is often accompanied by problems such as coating powdering and loss of gloss. When evaluating, it is necessary to combine indicators such as gloss retention and adhesion to comprehensively judge the degree of coating aging.
4.Does the coating thickness of a pre-coated coil affect its resistance to fading?
The coating thickness of color-coated coils is one of the important factors affecting their anti-fading performance, but it is not simply "the thicker the better". Instead, it shows a "positive correlation" within a reasonable range. After exceeding the critical point, the impact weakens or even produces a negative effect.
5.How to ensure the uniformity of coating thickness of color coated coils?
The uniformity of the coating thickness of the color-coated coil needs to be achieved through the whole process control of "no defects in the substrate → high-precision coating equipment → stable coating characteristics → uniform curing conditions → real-time monitoring and adjustment". The ultimate goal is: the thickness deviation in the transverse direction (width direction) is ≤±2μm, and the deviation in the longitudinal direction (length direction) is ≤±3μm per 10 meters, ensuring that the coating performance (anti-fading, weather resistance) of the product is uniform and consistent during subsequent processing (such as bending, cutting) and use.