A comparative study of the effects of laser wavelength on laser removal of chlorinated rubber

This paper compares the use of different lasers for the removal of Chlorinated Rubber CR. coatings from concrete surfaces. The work involves the investigation of basic phenomena and reactions of CR to various laser wavelengths, including CO2 10.6 mm., diode 810 nm.and ArF excimer 193 nm.laser radiation. Characteristics of beam absorption, residues and the thermal effects on the materials are analysed by optical microscopy, SEM and EDX. By calculating the thermal loading g. of the materials for the different lasers it has been revealed that the diode and excimer laser removal processes have very similar thermal loading with a g value of 1.2 kJrcm3 for the excimer laser and 1.5 kJrcm3 for the diode laser. The similarity of the two arises from the fact that this thermal loading is of the same order of magnitude as the dissociation energy of the primary bonds. The thermal loading for the CO2 laser process is around 100 Jrcm3, an order of magnitude smaller than the other two systems q1999 Elsevier Science B.V. All rights reserved