Weathering Ageing Test
Weathering is a routine performance test to determine durability of plastics under extreme weather conditions. The most popular areas for weathering studies are located in Arizona and South Florida. Samples can also be placed into weathering chambers performing accelerated tests to simulate changes in temperature, humidity and UV levels.
When plastics are used outdoors, weathering can damage general polymer properties. Most of the damage in plastics results from UV radiation. The extend of degradation varies depending upon the resin system, additives, colorants, stabilizers and processing conditions.
Typical effects may include:
- Surface Chalking
- Color & Gloss changes
Some colorants such as Carbon Black are UV absorbers which act as UV stabilizers. Other colorants which are not UV stable will undergo degradation and pigments and dyes will change color. Inorganic pigments tend to turn dark and dull, while organic pigments and dyes tend to fade in color. Thermoplastic and thermoset resins degrade and typically yellow upon exposure. The color would usually appear lighter in the L* value and yellower in the b* value.