Research On Laser Cleaning Of Chinese Painting And Galligraphy

Laser cleaning technology is a new cleaning technology which with rapid development in recent years. It is a novel non-contact cleaning method, which is characterized by environment-friendly and non-damage of basement. Because of its advantages, it will be widely used in more and more fields. In the field of protection and cleaning of historical relic, laser cleaning has a big advantage over the other cleaning methods.In this paper, laser cleaning was used in cleaning calligraphy and painting which is characterized by Chinese. The main pollution of calligraphy and painting is mildew. Based on the analysis of the adhesion action of mildew and rice paper basement, dry laser cleaning was used in the experiment. IR fiber laser and UV frequency tripled Nd:YAG laser were used in laser cleaning. The results of fiber laser cleaning experiment show that fiber laser is not suit of removal the mildew on the rice paper due to the thermal effect. The results of UV frequency tripled Nd:YAG laser The mechanism of laser cleaning is the ablation and thermal effect through the interacting of photon and mildew. It is demonstrated that laser cleaning, which with appropriate laser energy density and scanning times, can removal the mildew form the rice paper without any damage. The mildew residual rate in cleaning area was used in measurement the results of laser cleaning. Low repetition frequencies with several times and high repetition frequency with single, those experiments can removal the mildew clearly.The results of SEM show that there are some damages in the basement in repetition frequencies 40Hz experiment. The SEM image of repetition frequencies 20Hz is same as the basement rice paper without mildew. The results of FT-IR analysis show that, laser cleaning can recover the microstructure changes caused by mildew. There are some microstructure changes during the laser cleaning process.