UV Absorbers and Their Amounts

UV absorbers generally decrease the oxidative degradation of plastics and plastic-based composites. However, they do not always significantly change the fading of WPC materials. For example, wood flour (50% w/w, 40 mesh)-fllled HDPE (MFI 0.72) after an accelerating weathering in a box for 3000 h increased its L value by 115% after 

TABLE 16.7 Effect of a light stabilizer Cyasorb UV-3853 (Cytec) on fading of a wood-HDPE composite material 

More often, however, UV absorbers (or UV stabilizers) decrease fading quite noticeably (see, for example. Tables 16.7 and 16.8). 

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