Proceedings e report - Firenze University Press

N1--N4
WOOD SCIENCE FOR CONSERVATION OF CULTURAL HERITAGE
O2-I & O2-II
3rd ring
Bark
Tension wood
Heartwood
O1-I & O1-II
T1 -- T5
33
Saw by a circular
micro-saw
Radial
direction
Cut by a
razor blade
Fig. 4 Sampling for tests in longitudinal direction
Longitudinal
direction
In a second stage, the previously sample was polished in their longitudinal direction (direction of their
length). A rigid sample holder was designed to obtain a constant thickness along the entire length (Fig.
5).
Flexible plate
Fixation by screws
variable
Sample location
0.9mm
40-45mm
Fig. 5: Sample holder used for to polish the machined blocks at a constant section.
The size of wood samples was 35 x 1.8 x 0.9 mm 3 according to longitudinal, tangential and radial
direction respectively.
3.2. Sampling for tests in transverse directions
Samples were prepared with a diamond wire saw which produces parallel faces. For each type of
wood, two blocks were taken: one in the tangential direction and the other in the radial direction (Fig.
6). From these blocks, thin bars (longitudinal thickness) were cut at constant thickness.
One of the wood cross section was then polished to allow microscopic observations during tensile
tests. This operation was done with the same sample holder to ensure a uniform thickness over the
entire sample (Fig. 5).