UV aging test is a test method used to simulate the aging of materials under UV radiation in natural environments. It can be used to evaluate the performance changes of materials when exposed to UV radiation for a long time in outdoor environments. The ultraviolet aging test evaluates the weather resistance of materials by accelerating aging and subjecting them to long-term ultraviolet radiation in a short period of time.

Standards and scope of UV aging testing

Products from different industries will face the influence of light and heat in daily use, leading to aging and deterioration. UV aging testing has become the core method for testing durability. The anti-aging performance of materials is tested by simulating the cycle of ultraviolet light, temperature and humidity changes, and the service life of materials in natural environment is accurately predicted. The main points of application of main test standards are summarized.

The main international standards for UV aging testing

ASTM D4329/D4329M-13: Evaluating the aging performance of plastic materials under simulated natural ultraviolet radiation. This standard specifies the requirements for ultraviolet radiation intensity, test time, and other test parameters.

ASTM G154-16: This standard is applicable to the ultraviolet aging test of non-metallic materials. The standard specifies the requirements for testing equipment, including lamp arrangement, temperature control, and selection of testing parameters.

IS0 4892-3:2024: International standard, which applies to the aging test of plastic materials under laboratory light sources. The standard specifies the spectral distribution of the light source, the testing method for light intensity, and the selection of experimental parameters.

IEC 60068-2-5 (International Electrotechnical Commission): "Environmental testing - Part 2-5: Test methods - Test Sa: Simulating solar radiation on the ground", focuses on testing the UV aging resistance of components such as enclosures and cables for electronic and electrical products, and specifies requirements for temperature (55 ℃± 3 ℃) and irradiation intensity (1.12 W/m ² @ 300-400nm).

IEC612 (Photovoltaic Modules)

Single crystal silicon solar panels are required to undergo continuous exposure to 280-400nm spectral ultraviolet radiation at 85 ℃ to evaluate the UV resistance of packaging materials. The total radiation level tested is 38 kWh/m ², with a focus on testing the anti yellowing index of polyolefin backboards, which should be less than △ Y=2. The photovoltaic panel industry adopts this standard for mandatory sampling of each batch, forming a mutual recognition system with the national standard GB/T189.

ASTMG154 (General Version for Coating Testing)

The non-metallic surface coating is subjected to UVA-340 ultraviolet lamp exposure testing, with constant humidity (85 ± 5% RH) and increased surface stress during the dark condensation stage. The aging cycle is implemented according to this standard by switching the lighting and heat loss links every 14 hours, and the accuracy of the test results is 300% higher than that of outdoor exposure.

ISO 489 Automotive Parts Standard

Require exposure testing of short wavelength UVB at an intensity of 0.71W/m2, specifying the type of light source, irradiation intensity, and cycling conditions, and alternating with spraying cold water. Specially classify engine compartment sealant as a Class III hazardous material, and a mandatory quality inspection certificate must be provided with 50 cycles of no deformation or cracks observed.

SAE J252 Automotive Exterior Component Acceleration Test

The temperature control parameters specifically designed for car plastic instrument panels are a daytime surface temperature of 74 ℃, with three daily hot and cold switches to accelerate the stress release of resin materials. 70% of global car brands choose this alternative original parts certification standard.

National standard (mandatory for domestic enterprises)

GB/T 16422.3-2022 (Chinese National Standard): "Test Methods for Exposure of Plastic Laboratory Light Sources Part 3: Ultraviolet Fluorescent Lamps", equivalent to ISO 4892-3, applicable to the domestic plastic industry. It specifies the technical parameters of three types of filters, UVB-313, UVA-340, and UVA-351, as well as the parameter settings for two cyclic modes: "UV irradiation+condensation" and "UV irradiation+spray" (such as UV stage temperature of 50 ℃± 3 ℃ and condensation stage temperature of 40 ℃± 3 ℃);

-GB/T 1865-2009 (Artificial climate aging and artificial radiation exposure of paints and varnishes): For coating products, referring to ASTM G154, the conditions for UV aging testing are specified (such as UVA-340 irradiation intensity of 0.71 W/m ² @ 340nm, cycle time of 8h UV+4h condensation), and the criteria for determining color difference, powdering, adhesion and other results are clarified;

-GB/T 3512-2014 (Hot Air Accelerated Aging and Heat Resistance Test for Vulcanized Rubber or Thermoplastic Rubber): Appendix for UV Aging Test of Rubber, specifies the temperature (50 ℃± 2 ℃) under UVB-313 light source, test duration (usually 168h, 336h), and requirements for changes in hardness and tensile strength after aging.

Industry applicability and parameter selection logic

Calibration of weather resistance cycle for plastic products

The TPU external cable sheath is subject to the GOST 216 protection level evaluation method, which requires a 200H ultraviolet anti brittleness test. Ultraviolet radiation mainly affects the key difference in the proportion of PVC plasticizer loss and cross-linking reaction. When the DSC detection of the sample shows a decrease in crystallinity of ≥ 8%, it can be determined that the material has UV damage characteristics.

Outdoor LED display screen protection test

The polarizing film of the display screen glass needs to follow the ITB-V-130 test outline: Focus the UV-313 equivalent sunlight spectrum onto the sample surface and apply a tilted 45 degree strong pressure light source simulating 150 degrees of sunlight, and record the LAB color difference value index. The key color difference parameter adjustment range is △ E<2 (CIE chromaticity system detection standard). Electronic device manufacturers shall refer to the ETSI EN 606 series standards for joint reporting.

Key points of three proof test for coating layer

The weather resistant building materials varnish is tested in three stages according to the UVB exposure level in the building code JG T304. After the experiment, it is necessary to ensure that the Taber wear is within the range of 8 levels and no fish eye or mesh cracks are produced. The industry has specifically pointed out that the observation period for micro stress cracking of nano coatings needs to be extended from the standard 150H to the actual 600H to achieve equivalent certification values.

Application rules for special military equipment

The ship's sealing diagram adopts the UV-SSR series parameters in the mandatory standard GB242. After being exposed to ultraviolet radiation, a 20 hour salt spray alternating inspection process is maintained to ensure that the fluororubber material meets the specific technical requirements of a 60% elastic shape recovery value or above. The data needs to be verified three times with an error of no more than 0.15 before the conclusion parameters are reported.