Alexander Schnell & Lothar Goretzki 
Nd-YAG laser irradiation of pigments and binders in paint layers [EPUB ebook] 

Scientific Essay from the year 2003 in the subject Engineering — Civil Engineering, , course: EUROMAT 2003, language: English, abstract: Laser cleaning of polychrome surfaces is currently problematic due to the fact, that laser
irradiation can cause damage of the paint layers. A test program was worked out to
analyse the chemical and physical background of these typical “pigment blackening
effects”. The analytical methods ESEM, XRD, DTA, FTIR and NMR were used to
describe the reactions of inorganic pigments and organic binding media caused by laser
irradiation. The used laser system is commercially available, is currently used for the
cleaning of natural stone surfaces and works at a wavelength of 1064 nm. The
discoloration of pigments and paint layers was documented by colour measurement.
Further the measurement of discoloration thresholds of energy density (of pigments and
paint layers) was a main part of the research.