Numerical-experimental solar loading thermography method and chemical-physical techniques: A Tandem for the preservation of ancient books

In recent decades, the need to preliminarily study works of art with non-destructive and portable techniques has given rise to the figure of the conservation scientist for applications in the field of cultural heritage. This study applies solar loading thermography to detect surface and subsurface defects in an ancient book (1861), examining both natural degradation and fabricated defects. The latter were generated by the natural and inevitable degradation process to which the organic components of the book (for example cellulose, lignin, etc.) are subjected, and voluntarily introduced inside the book cover to determine the sensitivity and the feasibility of the technique. Thermal imaging analysis, supported by numerical simulation, revealed humidity damage and adhesive residues. Two experimental conditions were tested using or not clips to optimize cover-to-page adhesion. Four circoular dowels of different compositions assessed technique sensitivity. Complementary analyses (UV fluorescence, XRF spectroscopy, optical microscopy) validated surface anomal detection and material characterization.