Investigation of color protection of laminated glass by UV-blocking interlayers for conservation application

Abstract

The damaging of color pigments under UV radiation, usually called fading, is known, the most common is the loose of color intensity of clothes. A high UV-resistance of window and façade glazing is urgent for the conservation and preservation of historical exhibits and interiors. In this contribution, a long-lasting natural weather testing of several glass types, mostly LSG with different interlayer materials, and the effect of the different color patterns of paper and textile specimens are presented. According to the Harrison damage function, the initial damage level starts at 500 nm wavelength. Therefore, besides standard PVB-interlayer (UV-blocking from 360 to 380 nm wavelength) also special UV-blocking interlayer (UV-blocking from 400 nm) are part of the study. The research was conducted over the full summer of the year 2021. The assessment of the fading effect was measured as color spacing according to the CIELAB color space and verified by human eye perception. The CIELAB color space is the most used color system and combines brightness, yellow-blue and red-green tones. The research shows a significant effect of different glass build-ups on the color spacing value, especially for medium-sensitive pigment papers and textiles. Furthermore, the color shifting of single color scale samples showed demonstrated the limitation of the color spacing value of the CIELAB color space versus the human eye perception.