Neutron radiography as visualization and quantification method for conservation measures of wood firmness enhancement

Abstract

Different oils, waxes, natural and synthetic resins are in use for conservation and stability enhancement of degraded wood samples. X-ray radiography, tomography and thermography studies were carried out at several places as an attempt for the visualization of the conservation procedures. Because of the high sensitivity of neutrons in detecting hydrogen-containing materials, the visualization of their distribution can be obtained by means of neutron radiography at the NEUTRA facility of SINQ with good resolution. One of the most common conservation preservatives for wood consolidation is the acryl resin “Paraloid B-72”. Combined with different solvents in a variety of solvent mixtures, B-72 can be used to address a diversity of absorption, dispersion or evaporation determinants for different wooden objects. Therefore, four different acryl resin solvents of the same acryl resin applied to coniferous wood samples (4×4×2.7 cm) were investigated to determine the uptake and loss processes, followed by measuring sequences of images of the 2-dimensional distribution. This was done by creating image sequences showing the process of uptake and loss processes as two-dimensional distribution over about 20 h. The resin uptake depends strongly on the solvent, as well on the proportion of the resin in the composition. The acryl-ethylacetate composition has the lowest uptake, but the composition of 20% acryl 80% toluol has soaked up almost eight times more. Out of these results, a composition of 20% acryl and 80% toluol seems to be the best of the tried compositions, because the greatest part of resin remains and its allocation seems to be the most homogeneous as well.