Blue wool fading standard

The Fadeometer was equipped with a 2500 watt xenon-arc lamp and borosilicate inner and outer filters. Conditions of exposure were 63 +3 C and 65 + 5% R.H. The fabrics were exposed to light for 40, 80, 160, 320 and 640 AATCC Fading Units (AFU), as measured by AATCC Blue Wool Lightfastness Standards L-5, L-6, L-7, L-8 and L-9, respectively. The fabrics were padded with acid immediately prior to each 40 AFU of light exposure. For example, fabrics exposed for 80 AFU were padded with acid a total of 2 times fabrics exposed to 160 AFU were padded with acid 4 times. 

Although the importance of environmental factors (temperature, rela-- -tive humidity, airborne contaminants, and oxygen) that affect the fading of dyed textiles exposed to artificial and natural light indoors is well documented (1,2), relatively little information exists on the effectiveness of UV stabilizers incorporated into plastic films to minimize or retard such fading. To obtain this information, light-sensitive blue wool fabric (AATCC L-4 standard) was exposed to light from a xenon-arc source, with and without protection by clear cellulose acetate films... 

If the material becomes unserviceable before blue wool Standard 3 starts to fade visibly, it is placed in Feller s class C (Section 2.7) (Feller, 1978). If the material is more stable than Standard 3 but deteriorates before Standard 6 starts to fade, it is placed in class B. Those materials that survive as well or better than Standard 6 are placed in class A. Feller has suggested some standard polymer materials that can be compared to the material under test when light-ageing these are Paraloid B-72 for class A and poly(n-butyl methacrylate) (Elvacite 2044) for class B. 

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