Characterization of yarns from a Flemish tapestry of the XVIth century and a new Keratin/HNT protocol for the conservation of artwork

In this study, we proposed a physico-chemical approach for the characterization of yarns from a Flemish tapestry of the sixteenth century and a new conservation protocol for the preservation of the artwork. Thermogravimetric analysis (TGA) allowed us to identify yarn fibers and to estimate their life-time. The dynamic mechanical analysis (DMA) provided direct evidence on the aging effect on the yarns, their conservation state and their performance under different mechanical stresses [1]. Besides, the characterization path of yarns was relevant for proposing a novel conservation protocol based on keratin/HNT dispersions, which were explored for coating protection of wool threads. The aqueous dispersions were investigated by Differential Scanning Calorimetry (DSC) measurements to study the mixing enthalpy that can reflect the interaction between the two components in water. [2] The aesthetical effect of Keratin/HNT coating on wool thread was investigated by colorimetric analysis, optical microscopy and scanning electron microscope (SEM) revealing the HNT distribution in the wool fibers. The consolidation and protection effect of Halloysite/Keratin mixtures in wool thread samples were estimated by DMA before and after UV ray irradiation, as aging process. Moreover, the new procedure was tested on a historical yarn from a Flemish tapestry of the sixteenth century as conservation protocol. In conclusion, the results show that the proposed protocol for wool treatment is a promising material as a reinforcing coating for cultural heritage artwork, also increasing mechanical resistance and UV protection, with a minimal impact on the sample aesthetic aspects [3].