44 Table 7
Trees information for poplar cultivars and douglas-fir LVL
Wood Species Growth Site
Age years
dbh cm
Poplar cultivar A4A P. deltoids Bartr. x P. nigra L.
Bussy les Daours, Clarques and Argenton, France
12-13 41-49
Poplar cultivar Brenta P. deltoids Bartr. x P. nigra L.
Sainte Hermine and Saint Nicholas la Chapelle, France
18 43-50
Poplar cultivar I-214 P. deltoids Bartr. x P. nigra L.
Saint Nicholas la Chapelle and La Rèole, France
18 47-50
Poplar cultivar Koster P. deltoids Bartr. x P. nigra L.
Sainte Hermine and La Rèole, France 18
50-52 Poplar cultivar Lambro
P. deltoids Bartr. x P. nigra L. Sainte Hermine and La Rèole, France
17 47-53
Poplar cultivar Mella P. deltoids Bartr. x P. nigra L.
Saint Nicholas la Chapelle and La Rèole, France
17-18 39
Poplar cultivar Polargo P. deltoids Bartr. x P. nigra L.
Bussy les Daours, Epieds, and Saint Jean dAngely, France
13 44
Poplar cultivar Soligo P. deltoids Bartr. x P. nigra L.
Sainte Hermine and Saint Nicholas la Chapelle, France
18 48-54
Poplar cultivar Taro Populus sp. x Populus sp.
Saint Nicholas la Chapelle and La Rèole and Blanzay sur Boutonne, France
17-18 41-63
Poplar cultivar Triplo P. deltoids Bartr. x P. nigra L.
Vervant, Saint Jean dAngely and Bussy les Daours, France
13-14 38-47
Poplar cutivar Alcinde P. deltoids
Le Busseau, Vervant and Saint Jean d’Angely, France
13-19 46
Poplar cutivar Dvina P. deltoids
Sainte Hermine, Blanzay sur Boutonne and La Rèole, France
17-18 42-52
Poplar cutivar Lena P. deltoids
Sainte Hermine and La Rèole, France 17-18
52-58 Poplar cutivar Trichobel
P. trichocarpa x P. trichocarpa Le Busseau, Long and Vauchelle le Authis,
France 14-22
43-47 Douglas-fir
Pseudotsuga menziesii Cluny, France
26 34-35
After felling trees, the poplar and douglas-fir logs were debarked and cut in length of 60 cm for peeling process. The total logs were 38 pieces 33 poplar logs
and 5 douglas-fir logs. The sample logs were wrapped in plastics, kept cold, and maintained in the green condition before they were transported to the wood
workshop for the rotary cutting.
4.4 Method for production of sengon and jabon LVL
The peeling process and LVL production of sengon and jabon were performed at Division of Wood Quality Improvement, Forest Product Department
Faculty of Forestry Bogor Agricultural University, Indonesia.
4.4.1 Peeling process 4.4.1.1 Sengon and jabon logs preparation for rotary cutting
Tree rings have been used for a long time in areas outside the tropics to characterize the presence of juvenile and mature wood. Considering distinct
growth rings are absence in sengon and jabon trees, segmented ring was considered to be practically useful for characterizing their juvenility. A specified 1
cm width of segmented rings was made from pith to bark on the cross section of logs and numbered consecutively No. 1-7 as shown in Figure 10.
45 Sengon and jabon log sections bolts in length of 60 cm were taken from
each tree. Four bolts of about 28 cm in diameter were selected. The first two bolts were soaked in water at room temperature called unboiled, and the other
two bolts were subjected to boiling process in hot water at 75°C for 4 h called boiled. Subsequently, the bolts were peeled off to obtain veneers in the thickness
of 3mm. For each peeling, a sharp knife was used. The other factors such as knife angle, peeling angle, nose bar pressure, log temperature, peeling speed were kept
constant in the study. The knife angle was 20°, and peeling angle was 21°. The veneers were peeled using a spindle less rotary lathe. The bolts were peeled up to
core diameter of 6 to 8 cm in order to produce veneers from the 7 different segmented rings Figure 10. The veneers were collected and grouped for each
segmented rings and numbered consecutively from near the pith number 1 to near the bark number 7. LVL with the dimension of 20mm x 20mm x 500mm
from each segmented rings was produced.
4.4.2 LVL production, glue bond and bending strength tests 4.4.2.1 LVL production
The veneer specimens were conditioned at relative humidity RH of 85 and temperature of 25°C to an air-dry moisture content of 12. LVL panels with
dimension of 20x20x500 mm were manufactured by 3 mm veneer thick 7-ply at each segmented rings. Veneers were selected randomly in each segmented rings.
LVLs of 7 layers of 3 mm veneer were made, so that the target LVL thickness of 20 mm was achieved.
There were two different lay out that were used in this study. First lay out, LVL with loose side veneers glued with theirs tight side called type I. Second lay
out, LVL with loose side veneer glued with its loose side called type II see Figure 23
a b
Figure 23 Type I layout: loose-tight side lay out a and type II layout: loose-loose side lay out b
1
3 2
4 5
6 7
1
3 2
4 5
6 7
veneer adhesive
lathe check
