Study of ink laser removal processing effects on the surface and mechanical properties of aged paper

This paper presents a systematic investigation and parametric optimization of laser cleaning applied to aged and artificially ink-contaminated paper from the beginning of the twentieth century. A pulsed nanosecond Nd:YAG laser was used under the standard atmospheric conditions. The tests included microstructural analysis, laser cleaning, surface characterization, and tensile testing. A Taguchi design was applied to optimize the laser-cleaning process. This design includes principal component analysis (PCA) and gray relational analysis (GRA) to evaluate the influence of key process parameters on seven output responses. The results confirmed that laser cleaning can effectively remove ink residues while preserving the structural and mechanical integrity of paper. This study demonstrates that laser cleaning is a viable strategy for preserving aged documents. This study proposes a methodology that offers a model for similar historical and cultural heritage materials.