Physical properties and bonding quality of laminated veneer lumber produced with veneers peeled from small-diameter rubberwood logs

Abstract

The peeling of small-diameter rubberwood logs from the current short-rotation practices undoubtedly will produce lower grade veneers compared to the veneers from conventional planting rotation. Hence, this raises the question of the properties of the produced laminated veneer lumber (LVL) from veneers peeled from small-diameter rubberwood logs using the spindleless lathe technology. Different thicknesses of rubberwood veneers was peeled from rubberwood logs with diameter less than 20 cm using a spindleless lathe. Three-layer LVLs were prepared using phenol formaldehyde (PF) adhesive and hot pressed at different temperatures. During the peeling of veneer, lathe checks as deep as 30–60% of the veneer thickness are formed. Owing to deeper lathe check on 3 mm rubberwood veneer, higher pressing temperature significantly increased the gluebond shear strength of the PF-bonded LVL. In addition, lathe check frequency was also shown to influence the bond strength. The presence of higher lathe check frequency on 2 mm veneer increased the wettability, thus facilitating optimum penetration of adhesive for stronger bonding. These findings stress the importance of measuring and considering the lathe check depth and frequency during the lamination process to get a better understanding of bonding quality in veneer-based products.

Effect of Glue Spreads on the Structural Properties of Laminated Veneer Lumber from Spindleless Rotary Veneers Recovered from Short Rotation Hevea Plantation Logs

“…Based on Table 3, the percentage of radial swelling was 2.30% ± 0.30% and 4.47% ± 0.47%, tangential swelling was 0.54% ± 0.03% and 1.25% ± 0.10%, longitudinal swelling was 0.10% ± 0.03% and 0.13% ± 0.03%, and volumetric swelling was 3.19% ± 0.32% and 6.08% ± 0.65%, after two-and 24-h immersion, respectively. Compared to the result in Khoo et al [41], seven-ply rubberwood LVL was found to be more dimensionally stable compared to three-ply rubberwood LVL. The seven-ply rubberwood LVL has a significantly lower percentage of longitudinal swelling, tangential swelling and volumetric swelling, but a higher percentage of radial (thickness) swelling compared to the three-ply rubberwood LVL.…”

Performance of laminated veneer lumber panels from fast-growing species with different layering arrangements

“…In a study conducted by Prakash et al (2019), the feasibility of producing LVL from fast growing plantation timber (Melia dubia) was examined, with the conclusion that LVL could be utilized for door and window frame applications. Additionally, Khoo et al (2019) investigated the physical properties and bonding quality of LVL produced with veneers peeled from small-diameter rubberwood logs. However, while fast-growing trees can be a reliable resource for supplying wood for engineered wood products, it has been noted that the structural performance of such products may not meet the requirements for heavy timber structures (Rostampour Haftkhani and Hematabadi 2022).…”

Geometrical Parameters Optimization of Malaysia Rubber Wood through Honeycomb Structure as Composite Sandwich Core

“…With continuous research by scientists, rubber trees have been planted extensively in Southeastern Asia such as in Malaysia, Thailand and Indonesia to meet its ultra-high demand after it started gaining recognition in plantation forestry [1,2]. The wood from rubber trees is found to be a good raw material for the manufacturing industry for various forms such as sawn timber, plywood and laminated veneer lumber [3,4]. The sawn rubber wood can be made into furniture, flooring, parquet and interior construction elements [5,6].…”