scholarly journals Laminated veneer lumber from spindleless rotary-peeled veneers produced from short rotation, small Hevea plantation logs: Effects of lamination pressure

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 6735-6751
Author(s):  
Pui San Khoo ◽  
Kit Ling Chin ◽  
Paik San H'ng ◽  
Chuan Li Lee ◽  
Edi Suhaimi Bakar ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Specific Gravity ◽  
Physical And Mechanical Properties ◽  
Sudden Drop ◽  
Laminated Veneer Lumber ◽  
Short Rotation ◽  
Conventional Production ◽  
Veneer Surface ◽  
The Common ◽  
Shed Light

The invention of spindleless lathe technology has enabled veneers to be produced from small logs, such as logs from short rotation Hevea plantations, with low recovery loss. However, for structural laminated products, such as laminated veneer lumber (LVL), manufacturers are highly selective regarding the veneers for their conventional production. During the peeling process of small logs (< 18 cm), deeper and higher frequency of lathe checks were induced on veneer surface compared to the common log size used (> 30 cm). In this study, spindleless rotary-peeled veneers made from small rubber logs were processed into LVL using different lamination pressures: 7, 8, 9, and 10 kgf/cm2. The effects of lamination pressures on the physical and mechanical properties of the produced LVL were evaluated. Based on the findings, the specific gravity increased from 0.73 to 0.83 with increased lamination pressure. In terms of mechanical properties, all the values increased with lamination pressure, but with a sudden drop with 10 kgf/cm2. Understanding the effect of lamination pressure on the physical and mechanical properties can shed light on optimizing the usage of spindleless rotary-peeled veneers from small logs for the production LVL and other lamination products.

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

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3799
Author(s):  
Pui San Khoo ◽  
Kit Ling Chin ◽  
Chuan Li Lee ◽  
Paik San H’ng ◽  
Mohd Sahfani Hafizuddin
Keyword(s):  
Mechanical Properties ◽  
Small Diameter ◽  
Physical And Mechanical Properties ◽  
Longitudinal Axis ◽  
Modulus Of Rupture ◽  
Spread Rate ◽  
Minimum Requirement ◽  
Laminated Veneer Lumber ◽  
Short Rotation ◽  
Laminated Panels

Unproductive young rubber trees (15 years old) with smaller diameters (15 to 18 cm) compared to conventional rubber logs, harvested at the age of 25 years old, were selected for the production of laminated panels. Spindleless rotary veneer peeling was applied to logs from short-rotation rubber forest plantations to produce veneers for structural purposes. This raises questions about the utilization of these small-diameter logs with respect to its effect on the quality of veneer and laminated panels produced. This study examines the effect of the glue spread rates on the physical and mechanical properties of rubberwood laminated veneer lumber (LVL). Analysis of variance shows that the application of a 280 g/m2 glue spread rate significantly improved the density, water absorption and dimensional stability of rubberwood LVL. The mechanical properties of rubberwood LVL produced with a 200 g/m2 glue spread rate met the minimum requirement for the 2.1E-3100F stress class; 91.05 MPa for the modulus of rupture in the flatwise direction and 50.23 MPa for compressive strength parallel to the longitudinal axis. The modulus of elasticity in the flatwise direction of 11,189.55 MPa reached the minimum requirement for the 1.5E-2250F stress class.

scholarly journals Influence of Gluing Technology on Physical and Mechanical Properties of Laminated Veneer Lumber

2013 ◽  
Vol 64 (1) ◽  
pp. 33-38 ◽  
Author(s):  
Murčo Obućina ◽  
Goran Turk ◽  
Ejub Džaferović ◽  
Jože Resnik
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Laminated Veneer Lumber

scholarly journals Geomechanical characterization of lateritic hardpans from Bamendjou (West-Cameroon)

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Y. Ngueumdjo ◽  
V. H. Njuikom Djoumbi ◽  
V. Y. Katte ◽  
F. Ngapgue ◽  
A. S. L. Wouatong
Keyword(s):  
Mechanical Properties ◽  
Specific Gravity ◽  
Physical And Mechanical Properties ◽  
Western Region ◽  
Geochemical Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns ◽  
Geomechanical Characterization

AbstractThis study reports on the physical, mechanical, mineralogical and geochemical analysis carried out on four lateritic hardpan specimens from quarries in the Bamendjou area in the Western Region of Cameroon using common prescribed procedures. The results indicate that values of the bulk density, specific gravity, total and open porosities are very variable from one specimen to another. Meanwhile, the value of the compressive strengths of both the dry and immersed specimens were also very variable from one specimen to another, with the F2 and F1 specimens having higher values than the A1 and A2 specimens. All the specimens immersed in water recorded lower compressive strengths than the dry specimens. The flexural strengths also varied from one sample to another, with the F2 specimen having the highest resistance. The X-ray diffraction patterns reveal that the major peaks were assigned to gibbsite, goethite, and hematite, while the minor peaks were assigned to kaolinite and anatase. The mineralogy and geochemistry influenced the physical and mechanical properties, with the iron rich specimens having higher values in both the physical and mechanical properties than the alumina rich specimens. The results of the compressive strengths obtained were higher than (1–4) MPa obtained in Burkina Faso and India where they have been using latertic blocks for construction. Thus the hardpans of Bamendjou can also be exploited for building purposes conveniently.

Physical and Mechanical Properties of Hard Maple (Acer saccharum) and Yellow Poplar (Liriodendron tulipifera)

2020 ◽  
Vol 70 (3) ◽  
pp. 326-334
Author(s):  
Marly Gabriela Carmona Uzcategui ◽  
Roy Daniel Seale ◽  
Frederico José Nistal França
Keyword(s):  
United States ◽  
Mechanical Properties ◽  
Specific Gravity ◽  
Acer Saccharum ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Liriodendron Tulipifera ◽  
Eastern United States ◽  
Yellow Poplar ◽  
Clear Wood

Abstract Maple and poplar are common names of species that grow in the eastern United States. Physical and mechanical properties were evaluated from small clear wood specimens of hard maple (Acer saccharum) and yellow poplar (Liriodendron tulipifera). Specific gravity, static bending strength and modulus of elasticity, compression parallel and perpendicular to grain, and Janka hardness were tested. The experiments were carried out on defect-free specimens extracted from boards supplied by members of the Staircase Manufacturers Association. The material was donated by companies located in the eastern United States. On the basis of the findings, it can be stated that mechanical properties for maple and yellow poplar have not changed substantially because the average values remain in a range that is very close to the values published in previous studies.

scholarly journals Physical and mechanical properties of (Acacia auriculiformis x A mangium) hybrid Acacia

1970 ◽  
Vol 34 (2) ◽  
pp. 181-187 ◽  
Author(s):  
UK Rokeya ◽  
M Akter Hossain ◽  
M Rowson Ali ◽  
SP Paul
Keyword(s):  
Mechanical Properties ◽  
Specific Gravity ◽  
Acacia Mangium ◽  
Physical And Mechanical Properties ◽  
Tectona Grandis ◽  
Acacia Auriculiformis ◽  
Timber Species ◽  
Green Condition ◽  
Natural Crossing ◽  
Academy Of Sciences

The physical and mechanical properties of hybrid Acacia, produced from natural crossing between two introduced timber species (Acacia auriculiformis and Acacia mangium) were studied. The timber hybrid Acacia is of medium dense having specific gravity 0.56 at green condition which is less than that of teak (Tectona grandis). The volumetric shrinkage of hybrid Acacia wood was found greater than that of teak but the specific gravity was found less than that of teak. From the study of physical and mechanical properties it is evident that the species is moderately strong. The species is suitable for making furniture and other household articles. Key words: Hybrid Acacia; Specific gravity; Physical properties; Mechanical properties DOI: 10.3329/jbas.v34i2.6864Journal of Bangladesh Academy of Sciences, Vol. 34, No. 2, 181-187, 2010

Engineered Wood Composite of Laminated Veneer Lumber: Physical and Mechanical Properties

2016 ◽  
Vol 842 ◽  
pp. 103-128
Author(s):  
Kang Chiang Liew ◽  
Singan Grace
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Moisture Content ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
P Value ◽  
Thickness Swelling ◽  
Laminated Veneer Lumber ◽  
Physical Testing ◽  
Acacia Hybrid

Utilisation of forest plantation species such as Acacia hybrid has been used in wood-based industry as an alternative to solid wood that was usually attained from natural forest. While, the under-utilised species such as Mangifera sp. is not often been used as raw material for wood products, in this study, laminated veneer lumber (LVL) has been produced from Acacia hybrid and Mangifera sp. The physical and mechanical properties of LVL were determined and compared. For physical testing, the range value of moisture content was 9.41% to 14.56%, Density was 487.90 kg/m3 to 699.10 kg/m3, thickness swelling was between 0.20% to 6.05%, water absorption between 32.71% to 91.25%, and rate of delamination from 0% to 100%. Mangifera sp. LVL has higher moisture content, rate of delamination, and water absorbency. In mechanical testing, it is been found that Acacia hybrid LVL has overall higher strength compared to Mangifera sp. LVL, in terms of static bending strength (MOR and MOE), shear strength, and compression strength. Range of value for MOR was between 10.27 N/mm2 to 129.99 N/mm2, MOE between 1138 N/mm2 to 16472.93 N/mm2, shear strength between 0.43 N/mm2 to 3.40 N/mm2, and compression between 139.45 N/mm2 to 6749.74 N/mm2. For physical testing, the overall result of p-value for moisture content, water absorption, and delamination were significant at p ≤ 0.05, while density and thickness swelling were not significant at p ≥ 0.05. For overall result, the p-value for static bending strength (MOR and MOE) was significant at p ≤ 0.05 while for shear strength and compression strength were not significant at p ≥ 0.05.

Performance Evaluation of Flame-Retardant NSCFR-Treated Laminated Veneer Lumber(LVL) PartⅠ:Thermal, Physical and Mechanical Properties

2010 ◽  
Vol 168-170 ◽  
pp. 2106-2110
Author(s):  
Yi Qiang Wu ◽  
Chun Hua Yao ◽  
Yan Qing ◽  
Jian Xiong Lv ◽  
Yun Chu Hu
Keyword(s):  
Mechanical Properties ◽  
Water Immersion ◽  
Testing Machine ◽  
Fire Retardant ◽  
Physical And Mechanical Properties ◽  
Modulus Of Rupture ◽  
National Standard ◽  
Control Group ◽  
Mechanical And Thermal Properties ◽  
Laminated Veneer Lumber

This study aimed at evaluating the physical, mechanical and thermal properties of a structural laminated veneer lumber(LVL) prepared with self-made fire-retardant NSCFR being applied to the adhesive. Cone calorimeter(CONE), thermogravimetry(TG-DTG) and universal testing machine were utilized to assess the performances. Results showed that: fire-resistant and smoke-suppression characteristics of the fire-retardant treated LVL (FRLVL)were satisfactory. The heat release rate(HRR) of it was smaller than that of the untreated wood and it did not exhibit the typical second pkHRR of wood-based materials. It had a residual mass rate of 33.32% after exposure to fire. Overall production rate of CO and CO2, average specific extinction area and average smoke rate for it were remarkably less than that of unprocessed wood. In addition, FRLVL possesses acceptable physical and mechanical properties. It showed higher density and lower thickness swell after 24h water immersion than the control group and the strength parallel to glue-line parameters in static bending----modulus of rupture(MOR), modulus of elasticity(MOE), shear strength(SS) were 38.698 Mpa ,6.376 GPa and 4.389MPa separately, all of which met the corresponding requirements for structural LVL specified in the China National Standard GB/T 20241-2006.

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