The plastic is aging tested to achieve a satisfactory pass rate. Almost all plastic products need to be tested before leaving the factory. One reason for it is to increase product reliability. So far, there is no other choice. For new products, the performance of new parts or complete units needs to be evaluated. Exposing the defects of aging products before leaving the factory, such as solder joint reliability and product design, material and process defects can make the performance of aging products enter a stable range before leaving the factory and reduce the repair rate.
Why UV Accelerated Weathering Test is Needed?
When plastic is heated, it softens or melts. Especially when exposed to high temperature. Plastic is known to deteriorate rapidly when exposed to direct outdoor sunlight. Outdoor exposure and aging are the result of major factors such as UV radiation energy and actual usage conditions such as moisture, ozone, oxygen and heat. Considering the complex aging mechanism, it is necessary to conduct a comprehensive evaluation after having a basic understanding of the influence of various main factors on polymers. Therefore, in order to explain the complexity of the stability of polymers under the influence of various parameters, more basic information needs to be accumulated and efforts should be made to establish practical accelerated aging test methods.
The plastic UV aging tester can simulate the damage caused by sunlight, rain and dew to materials. UV uses fluorescent ultraviolet (UV) lamps to simulate the effect of sunlight, and uses cold to simulate moisture, rain and dew.
The material to be tested is placed in a cycle program of alternating light and moisture at a certain temperature for testing. UV can reproduce the hazards that occur outdoors for months to years after several days or weeks of testing.
Hazard types include: fading, discoloration, loss of gloss, chalking, cracking, clouding, blistering, embrittlement, strength loss and oxidation.
UV radiation from sunlight can have a variety of adverse effects on plastics, including:
Fade: UV radiation can cause fading or discoloration of plastics, especially those exposed to direct sunlight for extended periods of time. This can lead to loss of aesthetics and visual degradation of the plastics.Loss of strength and flexibility: UV radiation reduces the mechanical properties of plastics, including strength, flexibility and elongation. This results in reduced performance, structural integrity and service life of the plastics.
Surface Degradation: UV radiation can cause the surface of plastics to degrade, causing fibers to weaken and the surface to crack or flake off. This can result in a rough or frayed texture, reducing comfort and affecting the performance of the plastics.
Degradation of functional properties: UV radiation can also reduce the functional properties of plastics, such as water resistance, flame retardancy or antimicrobial properties, which may be important for specific applications. This can cause plastics to lose desired functionality and properties.
UV Accelerated Weathering Chamber and standard for Plastics
The ability of a plastic material to resist deterioration of its electrical, mechanical, and optical properties caused by exposure to light, heat, and water can be very signiﬁcant for many applications. This practice is intended to induce property changes associated with end-use conditions, including the effects of sunlight, moisture, and heat. The exposure used in this practice is not intended to simulate the deterioration caused by localized weather phenomena, such as, atmospheric pollution, biological attack, and saltwater exposure. Reproducibility of test results between laboratories has been shown to be good when the stability of materials is evaluated in terms of performance ranking compared to other materials. Therefore, exposure of a similar material of known performance (a control) at the same time as the test materials is strongly recommended. It is recommended that at least three replicates of each material be exposed to allow for statistical evaluation of results.
Use of ﬂuorescent UV apparatus that conforms to the requirements deﬁned in Practices G 151 and G 154 is required to conform to this practice. Unless otherwise speciﬁed, the spectral power distribution of the ﬂuorescent UV lamp shall conform to the requirements in Practice G 154 for a UVA 340 lamp. The following picture is a spectral irradiance plot for a typical UVA-340 lamp and benchmark solar radiation.
The size and shape of specimens to be exposed will be determined by the speciﬁcations of the particular test method used to evaluate the effects of the exposure on the specimens; the test method shall be determined by the parties concerned. Where practical, it is recommended that specimens be sized to ﬁt specimen holders and racks supplied with the exposure apparatus. Unless supplied with a speciﬁc backing as an integral part of the test, specimens shall be mounted so that only the minimum specimen area required for support by the holder shall be covered. This unexposed surface must not be used as part of the test area. For specimens of insulating materials, such as foams, maximum specimen thickness is 20 mm in order to allow for adequate heat transfer for condensation. Retain a supply of unexposed ﬁle specimens of all materials evaluated. Specimens should not be removed from the exposure apparatus for more than 24 h and then returned for additional tests, since this does not produce the same results on all materials as tests run without this type of interruption. When specimens are removed from the exposure apparatus for 24 h or more and then returned for additional exposure, report the elapsed time. Unless otherwise speciﬁed, program the device to one of the following test cycles. Operate the device continuously.
8 h UV with uninsulated black panel temperature controlled at 60-63°C
4 h condensation with uninsulated black panel temperature controlled at 50-6 3°C
(Used for most general applications)
8 h UV with uninsulated black panel temperature controlled at 70-63°C
4 h condensation with uninsulated black panel temperature controlled at 50-6 3°C
(Typically used for automotive applications) Note: Cycle B is equivalent to the exposure test cycle speciﬁed in SAE J2020.
8 h UV with uninsulated black panel temperature controlled at 50-63°C
4 h condensation with uninsulated black panel temperature controlled at 50-63°C
(Typically used for some plastic building products)
Practice G 154 lists several other exposure cycles that are used for ﬂuorescent UV exposures of nonmetallic materials.
LIB UV Accelerated Weathering Test Chamber
Main functions: In the plastic UV aging test machine, the fluorescent UV lamp can reproduce the effect of sunlight, and the condensation and water spray system can reproduce the effect of rain and dew. The temperature is controlled throughout the test cycle. A typical test cycle is usually UV light exposure at high temperature and a dark humid condensation cycle at 100% relative humidity; typical applications in paint coatings, automotive industry, plastic products, wood products, glue, etc.
Main features: Simulated sunlight: Ultraviolet rays in sunlight are the main factors that cause damage to the durability of most materials. We use UV lamps to simulate the short-wave UV portion of sunlight, which produces little energy in the visible or infrared spectrum. We can choose UV lamps with different wavelengths according to different test requirements, because each lamp has different total UV radiation energy and wavelength. Generally, UV lamps can be divided into two types: UVA and UVB.
Temperature control: In each cycle, the temperature can be controlled at a set point. At the same time, the black panel thermometer can monitor the temperature. The increase in temperature can accelerate the aging process. At the same time, the control of temperature is also very important for the reproducibility of the test.
Description of the main structure:
1.The test chamber is made of numerical control equipment, with advanced technology, smooth lines, and elegant appearance.
2.The material is thick 304SUS high-grade stainless steel.
3.The water level of the inner tank is automatically replenished to prevent damage to the heating tube when it is empty.
4.There are automatic nozzles installed inside the spray system, and the water pressure is adjustable.
5.LIB has designed a UV lamp current display meter on the control panel to remind the user to replace the new lamp according to the status.
6.LIB can customize the size, configuration, specimen holder and performance to fit your testing needs.
|Internal Dimension (mm)||450*1170*500|
|Overall Dimension (mm)||610*1330*1470|
|Specimen Holder Size(mm)||75*150|
|Specimen Capacity||56 Pieces|
|Irradiation Source||Fluorescent UV lamps (8) - 40 W|
|Temperature Range||Ambient ～ 90 ℃ ±2℃|
|Black Panel Temperature (BPT)||35 ～ 80 ℃|
|Humidity Range||≥95% RH|
|Bandwidth||290 ~ 400nm|
|Irradiance Control||0.3~20 W/㎡|
|Water Spray Cycle||1~9999H59M (Adjustable)|
|Distance of Specimen and lamp||50mm|
|Controller||Programmable color LCD touch screen controller, Ethernet connection|
|Water Supply System||Automatic water supply, Water purification system|
|Safety Device||Over-temperature Protection; Over-current Protection;|
|Water Shortage Protection; Earth leakage Protection; Phase Sequence Protection|
|Exterior Material||Steel Plate with protective coating|
|Interior Material||SUS304 stainless steel|
LIB UV Test Chamber is used to perform UV light accelerated weathering tests on the products and materials, can simulate the damage caused by UV light, temperature, humidity and rain. Model UV-SI-260 is widely used for weathering testing.
Contact us now and learn more information.