Figures & data
Figure 1. The blue sponge stored at Turin's Museum of Modern Art. The sponge is 22 cm in height and 15 cm in width; the total height of the object, from the base, is 37 cm (these are maximum dimensions).
Figure 2. Soiling of the samples for cleaning tests.
Figure 3. SFR laser, specimen with loosely-adhered dirt (right), irradiated with Fl = 2.8 J/cm2, E nom. = 450 mJ, spot = 4.5 mm, f = 1 Hz. On the left, a detail of the area after cleaning can be seen as a lighter blue (therefore altered) area.
Figure 4. SFR, loosely-adhered dirt applied on the right side of the glass slides. On the upper slide, the two spots (the first with one pulse, the second with five pulses) were obtained with Fl = 1 J/cm2, E = 350 mJ, spot = 4 mm, f = 1 Hz. On the slide below we can see a cleaned part using the same operating parameters.
Figure 5. LQS laser, specimen with loosely-adhered dirt. We cleaned the right side of the sample with Fl = 0.9 J/cm2, E = 250 mJ, spot = 6 mm, f = 5 Hz.
Figure 6. LQS laser, loosely-adhered dirt applied on the right side of the slides. Slide 1: the first spot obtained with Fl = 0.45 J/cm2, E = 130 mJ, spot = 6 mm, f = 5 Hz gave positive results. Slides 2,3,4: increasing fluence, energy, and did not give the same good results.
Figure 7. QS laser + water, specimen with adhered dirt. The irradiated area with Fl = 2.5 J/cm2, E = 300 mJ, spot 4 mm, f = 5 Hz. On the left, a detail after cleaning is shown.
Figure 8. QS Thunder Art laser applied to a, specimen with loosely-adhered dirt, using with Fl = 1.7 J/cm2, E = 329 mJ, spot 5 mm, F = 5 Hz. On the left, the detail shows that cleaning was completely successful.
Figure 9. QS Thunder Art laser applied to loosely-adhered dirt, on the right side of the slides. Slide 1: Fl = 1.2 J/cm2, E = 230 mJ, spot = 5 mm, f = 5 Hz. Slide 2: Fl = 1.7 J/cm2, E = 329 mJ, spot 5 mm, f = 5 Hz. Slide 3: Fl = 1.74 J/cm2, E = 342 mJ, spot = 5 mm, f = 5 Hz. Slide 4: Fl = 1.8 J/cm2, E = 362 mJ, spot = 5 mm, f = 5 Hz. Cleaning tests gave an increasing level of cleaning, without compromising or altering the paint film.
Figure 10. The sponge in the Museum of Modern Art before cleaning tests. Note the presence of fibers without color and of dust deposits.
Figure 11. Macro image of a portion of the sponge in the Museum of Modern Art before cleaning. Note the presence of dark particles on the surface.
Figure 12. Macro image of the sponge in the Museum of Modern Art after cleaning. (A) Magnified image after cleaning. (B) SEM back-scattered electron image of the surface after cleaning.
Figure 13. The sponge in Museum of Modern Art in Turin after treatment.
