Laser cleaning of artificially aged textiles

In order to analyse ancient textiles to identify the fibre, a proper cleaning of the sample is necessary. The anaerobic environment (i.e., the peatery), aiding the preservation of handmade textiles, often impregnates the textiles in such a way that the usual chemical procedures for cleaning are not sufficient while making the sample brittle. The use of laser pulses may offer an alternative method of cleaning. Four different textiles (wool, silk, flax, and cotton) have been investigated. As a first step we used laser irradiation on untreated samples to investigate the laser induced effects on textile materials. As a second step, consolidated samples, samples artificially aged (i.e., samples exposed to a lacustrine environment), and samples both artificially aged and consolidated were irradiated. Several combinations of the main laser parameters (energy density and number of pulses) were tested in order to find the best irradiation conditions. Scanning electron microscopy (SEM) was used to analyze the induced morphological changes. The obtained results are well reproducible while proving the very high efficiency in material removal of the laser pulses: in the four investigated textiles, the laser cleaning procedure permitted the identification of the fibres.