When the material is used outdoors, it will be exposed to sunlight or glass-filtered sunlight for a long time, and light, heat, humidity and other climate stresses will have a greater impact on the color and performance of the material. Therefore, the light, heat, humidity and other factors should be evaluated. The impact of climate stress on material properties becomes particularly important.
1) Lighting - Ultraviolet rays in sunlight are the main cause of photodegradation and photoaging of products. This is because the shorter the wavelength, the higher the energy and the stronger the penetration ability. In the solar spectrum (as shown below), ultraviolet rays happen to be waves with shorter wavelengths.
2) Heat - when the temperature increases, the destructive effect of light will also increase. Although the temperature does not affect the main photochemical reaction, it does affect the subsequent chemical reactions. The laboratory often accelerates the temperature by raising the temperature. Ageing.
3) Moisture - For materials used outdoors, when exposed to the sun in summer, they often encounter heavy rain, which causes the surface temperature of the material to drop sharply, causing thermal shock and stress corrosion. Dew is often more harmful to materials than rain. , because it adheres to the material longer, resulting in more severe moisture absorption.
Any one of these three factors will cause material aging, and in the actual use environment of materials, three or more environmental stresses often occur at the same time, causing harm to the material greater than any one factor acting alone. Therefore, in order to evaluate the service life of products in actual use, specific laboratory light source accelerated aging tests are usually used to evaluate the effects of light, heat, and humidity on the physical, chemical, and other properties of materials to ensure product quality.
UV aging test is a testing method to evaluate the resistance of new materials to UV light. It is usually tested in the laboratory through an accelerated UV aging test chamber. In a short period of time (weeks or months), reproducible and reliable aging test data can be obtained through UV aging testing; its short-wavelength UV light and condensation cycle system can realistically simulate the effects of sunlight, dew and rain on materials. destructive effect.
UV aging test mainly includes three modes: light, condensation and spray. The illumination stage is used to simulate daytime in the natural environment, and the light intensity and temperature can be controlled during illumination; the condensation stage is used to simulate the phenomenon of dew condensation on the sample surface at night. During the condensation stage, the UV lamp is turned off (dark state) and only the test temperature is controlled; spray In this stage, a rainy environment is simulated by continuously spraying water on the surface of the sample.
There are three common types of UV lamps, namely UVA-340, UVA351 and UVB313. The light emitted by all lamps is ultraviolet light, but their spectral distribution and total energy of the emitted light are different, so the test should be based on the actual situation. Select appropriate lamps for simulation testing.
The spectral distribution of UVA-340 lamps is similar to the ultraviolet band of outdoor sunlight, and is generally used for photoaging tests of conventional outdoor products;
UVA-351 lamps can simulate the ultraviolet part of sunlight passing through glass windows, and are mainly used for the aging of indoor products;
UVB-313 lamps can produce short-wave ultraviolet rays, which can age materials faster than UVA lamps, thus achieving the purpose of accelerating aging. They are widely used in fast and time-saving testing of durable materials.
UV aging test chamber can meet your needs for UV aging test of materials;
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