Ultraviolet Absorbers: A Treatment to Reduce Fading and Degradation of Textiles

Fiber artists, as well as museum personnel, have attempted to reduce fading and/or deterioration in textiles by 1) using lower levels of lighting, 2) using incandescent lights instead of fluorescent lights, and 3) using ultraviolet filters on fluorescent lights. However, in many public buildings and in some daylighted museum galleries, textiles may be displayed without protection from light by any of the above measures. Therefore, many contemporary textiles are subjected to unusually high levels of lighting because most North American buildings are well lighted by fluorescent lamps and/or daylight through large expanses of window glass that emit or transmit sizable amounts of ultraviolet radiation. Ultraviolet radiation is particularly damaging to textiles, paper and other organic materials because it is capable of inducing photochemical changes that result in fading and strength loss. This study examined ultraviolet absorbers as an alternative method for reducing light-induced fading and degradation. Most ultraviolet absorbers commercially available in the United States were initially screened for potential use on textiles on the basis of color, toxicity, solubility, and ability to reduce fading. After preliminary evaluations, four benzophenone-based absorbers were selected for further study. The UV absorbers were applied to colored wool textiles plus undyed cotton, linen, silk and wool by an immersion procedure. After treatment the specimens were exposed to light in a xenon-arc Weather-Ometer, an accelerated lightfastness testing instrument. Total color change was instrumentally measured using a HunterLab tristimulus colorimeter. Strength loss was evaluated by breaking strength tests using a CRE Scott Tester. Results showed that three of the UV absorbers modestly reduced fading in approximately fifty percent of the dyed wool specimens and slightly suppressed degradation in the undyed fibers. The treatment shows promise for use on wool textiles such as tapestries colored with natural dyes