Impact of washing and aging process on the physical and mechanical properties of pre-Hispanic fabrics found in the Museum of Site and Archeological Sanctuary of Pachacamac, Perú

Conservation of textiles is indubitably a delicate and relevant matter, as its focus is to preserve pieces that carry unmeasurable historical value. This work aims to evaluate the impact of washing and aging processes in the conservation of archaeological textiles. The samples used are Peruvian textiles found in the Museum of Site and Archeological Sanctuary of Pachacamac, located in the Lurín district, city of Lima, Perú. The museum's cleaning protocol was replicated using the immersion washing method with Orvus WA paste as a surfactant at concentrations of 0.5% and 1% w/w. Samples analyzed conditions included: unwashed control samples, samples washed with both concentrations, and samples washed and followed by a prolonged light exposure aging. Evaluated parameters were changes in tonality by conducting surface analysis through scanning electron microscopy and image processing, determining the crystallinity index using the X-ray diffraction method, analyzing surface properties via X-ray energy dispersion spectroscopy, and mechanical properties by tensile testing The obtained results show the effective removal of surface particles, mostly soluble salts. Prolonged light exposure caused a loss of color saturation on the textile due to photodegradation. Meanwhile, the washing process with a 1% surfactant concentration showed no loss in the mechanical properties; furthermore, previously washed aged samples showed the ability to better withstand the aging and photodegradation process and better retain their mechanical properties compared to the untreated uncleaned sample.