Principle of UV weathering test, UV weathering test chamber

The principle of UV weathering test is the principle of UV weathering test; the UV weathering test equipment is another kind of light aging test equipment which mainly simulates the UV light in the sun At the same time, it can reproduce the damage caused by rain and dew The equipment tests by exposing the materials to be tested to the controlled interactive cycle of sunlight and moisture, and increasing the temperature at the same time The equipment adopts ultraviolet fluorescence ultraviolet climate resistance test equipment, which is another kind of light aging test equipment simulating the light, mainly simulating the ultraviolet light in the sunlight At the same time, it can reproduce the damage caused by rain and dew The equipment tests by exposing the materials to be tested to the controlled interactive cycle of sunlight and moisture, and increasing the temperature at the same time The equipment adopts ultraviolet fluorescent lamp to simulate sunlight, and can also simulate the influence of moisture by condensation or spray In just a few days or weeks, the device can reproduce the damage that would take months or years outdoors The damage mainly includes discoloration, discoloration, brightness reduction, pulverization, crazing, blurring, embrittlement, strength reduction and oxidation The test data provided by the equipment is of great help to the selection of new materials, the improvement of existing materials or the evaluation of composition changes that affect the durability of products The device is a great predictor of the changes the product will encounter outdoors Although ultraviolet (UV) only accounts for 5% of sunlight, it is the main light factor that causes the durability of outdoor products to decline This is because the photochemical effect of sunlight increases with the decrease of wavelength Therefore, it is not necessary to reproduce the whole spectrum of sunlight when simulating the damage effect of sunlight on the physical properties of materials In most cases, we only need to simulate the UV light of short wave The reason why UV lamps are used in UV accelerated weathering tester is that they are more stable than other lamps and can reproduce the test results better It is a good method for Zui to use fluorescent UV lamp to simulate the influence of sunlight on physical properties, such as brightness decline, cracking, peeling and so on There are several different UV lights to choose from Most of these UV lamps mainly produce ultraviolet light, not visible light and infrared light The main difference of lamps is reflected in the difference of the total UV energy they produce in their respective wavelength range Different lamps will produce different test results The actual exposure application environment can indicate which type of UV lamp should be selected UVA-340, the best choice for Zui to simulate sunlight and ultraviolet UVA-340 can perfectly simulate the sunlight spectrum in the critical short wave wavelength range, that is, the spectrum in the wavelength range of 295-360nm UVA-340 only produces the spectrum of UV wavelength that can be found in sunlight UVB-313, which is used in Zui accelerated test, can provide test results quickly They use shorter wavelength UVs that are stronger than those commonly found on earth Although these UVs, which are much longer than natural waves, can accelerate the experiment to a large extent, they will also cause degradation damage to some materials The standard defines a fluorescent UV lamp that emits less than 2% of the total output light energy and is generally called a UV-A lamp; a fluorescent UV lamp that emits less than 10% of the total output light energy and is generally called a UV-B lamp; the wavelength range of UV-A is 315-400nm; the wavelength range of UV-B is 280-315nm Outdoor materials can be exposed to moisture for up to 12 hours a day The results show that the main cause of outdoor humidity is dew, not rain The UV accelerated weathering tester simulates the influence of outdoor humidity through a series of unique condensation principles In the condensation cycle circle of the equipment, there is a water storage tank at the bottom of the box body, which is heated to generate water vapor The hot steam keeps the relative humidity in the test chamber at 100% and a relative high temperature The design of the product ensures that the test piece actually forms the side wall of the chamber, so that the back of the test piece is exposed to the indoor ambient air The cooling effect of the indoor air causes the surface temperature of the test piece to drop to a level several degrees below the steam temperature The appearance of this temperature difference results in the condensation of liquid water on the surface of the specimen during the whole condensation cycle This condensation product is very stable pure distilled water This kind of pure water can improve the reproducibility of the experiment and avoid the problem of water stain Because the outdoor exposure time can be as long as 12 hours a day, the humidity cycle of UV accelerated weathering testing machine generally lasts for several hours We recommend that each condensation cycle last at least 4 hours It is noted that UV exposure and condensation exposure in the equipment are carried out respectively, which are consistent with the actual climatic conditions For some applications, water spray can better simulate the environmental conditions of Zui Water spray is very useful to simulate the mechanical erosion caused by temperature change and rainwater erosion UV accelerated weathering tester / spray type is specially designed to reproduce this condition Due to the frequent erosion from rainwater, the coating layer of wood, including paint and colorant, will appear corresponding erosion phenomenon Recent research shows that this kind of rain wash action can wash off the coating layer with anti degradation effect on the surface of the material, thus directly exposing the material itself to the destructive influence of UV and moisture This process can be repeated many times, resulting in a material degradation phenomenon, which can not be reproduced by condensation alone The advantages of fluorescent lamp are: fast obtaining test results; simplified illumination control; stable spectrum; little maintenance; low price and reasonable operation cost There is only a small part of the land on the earth, and most of the land is the sea Therefore, the marine climate is a climate environment that has a great impact on human life and material products.