How does UV Accelerated Weathering Tester choose a light source?

What aging factors are simulated by UV Accelerated Weathering Tester? During the use of polymer materials, many factors in the climate environment may have an effect on the aging of polymer materials. If the main factors that cause aging are known in advance, the test method can be selected in a targeted manner.

We can determine the test method from the transportation, storage, use environment and aging mechanism of the material. For example, hard polyvinyl chloride profiles are processed by using polyvinyl chloride as raw material and adding stabilizers, pigments and other additives, and are mainly used for outdoor use. Considering the aging mechanism of polyvinyl chloride, polyvinyl chloride is easily decomposed when heated; considering the use environment; oxygen, ultraviolet light, heat and moisture in the air are all causes of the aging of profiles.

Therefore, the national standard GB/T8814-2004 "Unplasticized Polyvinyl Chloride (PVC-U) Profiles for Doors and Windows" not only stipulates the photo-oxidative aging test method, but adopts GB/T16422.2 "Plastic Laboratory Light Source Exposure Test" The second part of the method: xenon arc lamp "aging for 4000h or 6000h, simulating outdoor ultraviolet light and visible light, temperature, humidity, rainfall and other factors, and specifying the thermo-oxidative aging items: after heating, placed at 150 ℃ for 30 minutes, and visual observation Whether there are bubbles, cracks, pitting or separation, to investigate the heat resistance of the profile.

Another example is my country's competitive product in the international market: foreign trade export shoes. In the process of use, the ultraviolet rays in the sun are the main reasons for the discoloration and fading of shoes. Therefore, it is necessary to use an ultraviolet light box to test them for yellowing resistance.

The commonly used footwear yellowing resistance test box uses a 30W UV lamp, the sample is 20cm away from the light source, and the color change is observed after 3 hours of irradiation. At the same time, during transportation, the sultry and humid environment in the container will cause discoloration, spots, and even deterioration of shoe uppers, soles, and glue. Therefore, before shipment and transportation, it is necessary to consider the humidity and heat aging test, simulate the high heat and high humidity environment in the container, and observe the appearance and color change after 48h test under the condition of 70℃ and 95% relative humidity.

For more information about UV Accelerated Weathering Tester, please pay attention to QINSUN instrument!

2022-02-16 15:19