The UV aging test chamber is another light-simulating light aging test equipment, which mainly simulates ultraviolet light in sunlight. It also reproduces the damage caused by rain and dew. The equipment is tested by exposing the material under test to a controlled alternating cycle of sunlight and humidity while increasing the temperature. The device uses ultraviolet fluorescent lamps to simulate sunlight and can also simulate the effect of moisture from condensation or spray.
Main Parameters of UV Aging Test Chamber:
01. Light Source:
Lamp wavelength: UVA-340/UVB-313; number of lamps: 8; lamp power: 40W/pc;
02. Simulated environment: temperature, humidity, light, spray, condensation;
03. Temperature range: RT+10℃～ 70℃;
04. Humidity range: ≥95%RH ;
05. Temperature variation: ≤±0.5℃;
06. Temperature uniformity: ≤±2℃;
07. Blackboard temperature: 40℃~65 ℃;
08. Distance between lamp tubes: 35mm;
09. Test time: 1~9999S, M, H is adjustable;
10. Number of samples: about 40 pieces ;
11. Irradiance range: <50W /㎡.
In just days or weeks, devices can reproduce the damage that takes months or years outdoors. The damage caused mainly includes fading, discoloration, reduction of brightness, powdering, cracking, fading, embrittlement, strength reduction and oxidation. The test data provided by the equipment can be very helpful when selecting new materials, improving existing materials or evaluating compositional changes that affect product durability. Devices are excellent in het predict the changes a product will encounter outdoors.
Although ultraviolet light (UV) accounts for only 5% of sunlight, it is the most important light factor that determines the durability of outdoor products. Thisbecause the photochemical influence of sunlight increases as the wavelength decreases. Therefore, when simulating the destructive effect of sunlight on the physical properties of materials, it is not necessary to reproduce the entire sunlight spectrum. In most cases, only short-wavelength UV light is needed. The reason why the ultraviolet light accelerated weather resistance testing machine uses UV lamps is that they are better than others. Lamps are more stable and provide better reproducibility of test results. Using fluorescent UV lamps to simulate the impact of sunlight on physical properties such as brightness drop, cracking, peeling, etc. is the best practice. There are vdifferent UV lamps to choose from. Most of these UV lamps produce mainly ultraviolet light instead of visible and infrared light. Lamps differ primarily in the total UV energy they produce in their respective wavelength ranges. Different lamps will produce different test results. The actual exposure application environment may dictate the type of UV lamp to use.
UVA-340, the best choice for simulating sunlight UV
UVA-340 is excellent for simulating of the critical short-wavelength range The sunlight spectrum, ie the spectrum with a wavelength range of 295-360 nm, the UVA-340 only produces a spectrum of UV wavelengths that can be found in sunlight.
UVB-313 for accelerated testing
UVB-313 can provide test results very quickly. The short wavelength UV light they use is more intense than the UV lightwaves typically found on Earth today. While these UV lamps, which are much shorter than the natural wavelength, can speed up the test significantly, they can also cause inconsistent and realistic degradation damage to some materials.
The standard defines a fluorescent ultraviolet lamp that emits light energy below 300 nm and accounts for less than 2% of the total light output.rgy, commonly referred to as a UVA lamp; the light energy emitted below 300nm is greater than that of a fluorescent ultraviolet lamp with 10% of the total output light energy, commonly called UVB lamp;
UV differentiates UVA wavelength range from 315- 400nm; UVB wavelength range of 280-315 nm ;
Exterior materials can be in contact with moisture for up to 12 hours a day. Research results show that the main cause of this outdoor humidity is dew, not rain. The UV accelerated weathering tester simulatesthe influence of outdoor moisture through a series of unique condensation principles. In the condensing cycle of the equipment, there is a water storage tank at the bottom of the box, which is heated to generate water vapor. The hot steam maintains the relative humidity in the test chamber at 100% and maintains a relatively high temperature. The design of the product ensures that the test piece actually forms the side walls of the chamber, so that the back of the test piece is exposed to the ambient air in the chamber. Due to the cooling effect of the ambient air, the surface temperature of the test piece drops to a few degrees below the steam temperature. The occurrence of this temperature difference causes liquid water to condense on the surface of the sample throughout the condensation cycle. The product of this condensation is very stable pure distilled water. This pure water increases test reproducibility while eliminating water problemsstains are avoided.
Since exposure to outdoor humidity can be as long as 12 hours per day, the humidity cycle of the UV Accelerated Weathering Tester generally lasts several hours. We recommend that each condensing cycle lasts at least 4 hours. Note that the UV exposure and the condensation exposure in the equipment are performed separately, which is consistent with the actual climate conditions.
For some applications, water mist may better simulate end-use environmental conditions. Water spray is extremely useful in simulating mechanical erosion from temperature fluctuations and erosion from rain. The UV accelerated weathering tester/spray type is specifically designed to reproduce this condition.
Due to the constant erosion by rainwater, the coating layer of wood, including paint and stain, will corrode accordingly. Recent research has shown that this rain-scouring action reduces the anti-ddegradation coating layer on the surface of the material can wash away, exposing the material itself directly to the harmful effects of UV and moisture. This process can be repeated many times, resulting in a material degradation phenomenon that cannot be reproduced by condensation alone.