Theoretical model and experimental study for dry and steam laser cleaning

Dry and steam laser cleaning was investigated both theoretically and experimentally. The experimental results show that cleaning efficiency increases with increasing laser fluence or decreasing laser wavelength. The cleaning thresholds exist both dry and steam laser cleaning. A cleaning model was established for laser-induced removal of particles from solid surfaces by taking adhesion force, such as Van der Waals force and capillary force, and cleaning force into account. Laser cleaning forces are induced by fast thermal expansion of particles and/or solid surfaces irradiated by laser for dry laser cleaning and evaporating liquid film heated by laser irradiation for steam laser cleaning, respectively. It was found that laser cleaning forces increase with an increase of laser fluence. At the same laser fluence, cleaning forces increase with decreasing laser wavelength. Cleaning thresholds can be obtained by comparing cleaning force and adhesion force. The experimental results are good consistent with the theoretical analysis.