Cyclododecane as opacifier for digitalization of archaeological glass

Abstract

-This paper faces the problem of acquiring archaeological artifacts using triangulation based 3D laser scanners and focusing on reflective/refractive surfaces. This kind of artifacts are mostly made of glass or polished metal, and the properties of their surfaces violate most of the fundamental assumptions made by vision algorithms. Also, the unique and fragile nature of archaeological artifacts adds an extra limitation to the acquisition process: using industrial whitening sprays has to be avoided, due to the physicochemical processes required to clean the surface after scanning and because the chemical properties of these sprays may damage the original object. As an alternative to them, a new application of a common conservation material is proposed: the use of cyclododecane as a whitening spray. Thanks to its chemical stability and to the fact that it sublimes at room temperature, together with its good film-forming capabilities, a set of evaluation tests is presented to prove that the error introduced by the opaque thin layer created on the surface of the artifact is smaller than the accuracy of the 3D scanner and, thus, no acquisition errors are introduced. A comparison with general-purpose industrial whitening sprays is also presented, and achieved results show no significant differences in the quality of the resulting 3D models.

Studies of internal stress induced by solidification of menthol melt as temporary consolidant in archaeological excavations using resistance strain gauge method

“…Cyclododecane (CDD) [14][15][16][17][18][19][20][21] and menthol [22][23][24][25] , also referred as "volatile binder media" [23][24] , are mostly used temporary consolidants. In typical applications, the material is melted and applied on the target cultural relics.…”

“…Thus, it arouses our attention and interest in investigating possible internal stress induced on the artifacts during temporary consolidation practice. Although successful applications of CDD and menthol as consolidant have demonstrated their safety to cultural heritages [14][15][16][17][18][19][20][21][22][23][24][25] , vital information about the internal stress such as generation mechanism, magnitude and distribution, which can be interesting and helpful to conservators, is still unclear.…”

Studies of internal stress induced by solidification of menthol melt as temporary consolidant in archaeological excavations using resistance strain gauge method

“…Recently, on-site temporary consolidation has attracted more and more attention due to its reversibility. Cyclododecane (CDD) [14][15][16][17][18][19][20][21] and menthol [22][23][24][25], also referred as "volatile binder media" [23,24], are mostly used temporary consolidants. In typical applications, the material is melted and applied on the target cultural relics.…”

“…Thus, it arouses our attention and interest in investigating possible internal stress induced on the artifacts during temporary consolidation practice. Although successful applications of CDD and menthol as consolidant have demonstrated their safety to cultural heritages [14][15][16][17][18][19][20][21][22][23][24][25], vital information about the internal stress such as generation mechanism, magnitude and distribution, which can be interesting and helpful to conservators, is still unclear.…”

Effects of different coating materials on three-dimensional optical scanning accuracy

“…A traditional approach used to resolve both the problem of transparency of the surface and the specular reflection is to apply coating materials. [16][17][18] Palousek et al 17 evaluated the measurement deviation in a 3D digitizing process of glossy surfaces coated with titanium dioxide (0.003 mm) and chalk powder spray (0.044 mm). The authors point that the chalk powder contains particles of approximately 0.009 mm, which, after application, remain sharply defined on the surface, and smaller particles, which form islets and a characteristic spatter diameter of up to 0.050 mm.…”