ASTM G154, ASTM D4329, ASTM D4587, ISO 4892 QUV Accelerated Weathering

Scope:

ASTM G154, ASTM D4329, ASTM D4587 test is done by subjecting test samples to differing levels of the most destructive components of weathering – ultraviolet radiation, moisture, and heat. The process of determining the effects of materials under certain environmental conditions is termed accelerated weathering. In this test method, UV radiation is generated from fluorescent lamps, moisture from forced condensation, and heat from installed heaters inside the QUV test chamber. 

Performance under simulated conditions of rapid weathering can be compared to the performance of materials and coatings exposed to prolonged periods of real-world exposure. The various test standards include: ASTM G154, ASTM D4329, ASTM D4587, ISO 4892, SAE J2020.

Test Procedure:

For the ASTM G154, ASTM D4329, ASTM D4587 test approximately 20 test samples are placed in the QUV and put through a cycle of exposure to extreme ultraviolet radiation exposure accompanied by condensation moisture exposure. Based on the expected end-use conditions, different cycles are defined; for example, a common period for automobile exterior applications will be 8 hours of UV exposure at 70° C followed by 4 hours of condensation at 50° C. These loops will be repeated for prolonged amounts of time, potentially thousands of hours, simulating much longer periods in the physical world.

Specimen size:

For rapid weathering tests, flat plaques or disks are often used. Normal sample holders can hold one sample measuring 3 X 12 inches (75 X 300 mm) or two samples measuring 3 X 6 inches (75 X 150 mm). Parts of various sizes can be compensated.

Data:

Exposed samples from accelerated weathering conditions can be compared to unexposed control samples. Several exposure times (such as 500, 1000, and 2000 hours) are often compared to each other. Based on the performance criteria, such comparison can include measures of Haze, Transmission, Yellowness Index, Color Change, and/or physical properties including Impact Strength.

Conclusion:

Hence, ASTM G154, ASTM D4329, ASTM D4587 is a standard test method that determines accelerated weathering and simulates damaging effects of long term outdoor exposure of materials and coatings.