scholarly journals Optimization of Press time and Properties of Laminated Veneer Lumber Panels by Means of a Punching Technique

BioResources ◽  
2017 ◽  
Vol 12 (2) ◽  
Author(s):  
Halimeh Pangh ◽  
Kazem Doosthoseini
Keyword(s):  
Laminated Veneer Lumber ◽  
Press Time

scholarly journals Improved strength properties of LVL glued using PVAc adhesives with physical treatment-based Rubberwood (Hevea brasiliensis)

2020 ◽  
Vol 5 (1) ◽  
pp. 711-725
Author(s):  
Sutrisno ◽  
Eka Mulya Alamsyah ◽  
Ginanjar Gumilar ◽  
Takashi Tanaka ◽  
Masaaki Yamada
Keyword(s):  
Shear Strength ◽  
Hevea Brasiliensis ◽  
Formaldehyde Emission ◽  
Strength Properties ◽  
Modulus Of Rupture ◽  
Horizontal Shear ◽  
Physical Treatment ◽  
Cold Pressing ◽  
Laminated Veneer Lumber ◽  
Pressing Time

AbstractThe properties of the laminated veneer lumber (LVL) composed of the boiled veneer of Rubberwood (Hevea brasiliensis) using polyvinyl acetate (PVAc) adhesives in various cold-pressing time and various conditioned time with loaded and unloaded were studied. Five-ply LVL was produced by boiling veneer at 100°C for 90 min as pretreatment and cold-pressing time at 12 kgf cm−2 for 1.5, 6, 18, and 24 h then conditioned at 20°C and 65% relative humidity (RH) with loaded (12 kgf cm−2) and unloaded for 7 days as physical treatment. Especially for the delamination test, the specimens were immersed at 70 ± 3°C for 2 h and dried in the oven at 60 ± 3°C for 24 h; then, the specimens were solidified at room temperature (20°C and 65% RH) with loaded (12 kgf cm−2) and unloaded for 7, 10, 12, and 14 days. To determine the performance of LVL, the density, moisture content (MC), delamination, modulus of elasticity (MOE), modulus of rupture (MOR), horizontal shear strength, and formaldehyde emission tests were conducted according to the Japanese Agricultural Standard (JAS 2008) for structural LVL. The MOE and MOR values were significantly influenced by the physical treatment, however, neither to horizontal shear strength nor to formaldehyde emission. The best performance of LVL has resulted from unloaded LVL with cold-pressed time for 18 h; the MOE and MOR values were 9,345.05 ± 141.61 N mm−2 and 80.67 ± 1.77 N mm−2, respectively. The best value of the horizontal shear strength was obtained from the LVL with 18 h cold-pressing time and conditioned with loaded (13.10 ± 1.47 N mm−2) and unloaded (12.23 ± 1.36 N mm−2). The percentage of delamination values decreased with an increase in the cold-pressing time and conditioning time. The lowest value of delamination (19.06%) was obtained from the LVL with 24 h cold-pressing time and conditioned with loaded for 14 days. Except the delamination test, all other properties fulfilled the JAS.

scholarly journals Innovative concepts for the usage of veneer-based hybrid materials in vehicle structures

2021 ◽  
pp. 146442072199839
Author(s):  
DB Heyner ◽  
G Piazza ◽  
E Beeh ◽  
G Seidel ◽  
HE Friedrich ◽  
...  
Keyword(s):  
Steel Strip ◽  
High Energy ◽  
The Body ◽  
Vehicle Body ◽  
Material System ◽  
Laminated Veneer Lumber ◽  
Hybrid Beam ◽  
Bending Load ◽  
The Impact ◽  
Very High

A promising approach for the development of sustainable and resource-saving alternatives to conventional material solutions in vehicle structures is the use of renewable raw materials. One group of materials that has particular potential for this application is wood. The specific material properties of wood in the longitudinal fiber direction are comparable to typical construction materials such as steel or aluminum. Due to its comparatively low density, there is a very high lightweight construction potential especially for bending load cases. Structural components of the vehicle body are exposed to very high mechanical loads in the case of crash impact. Depending on the component under consideration, energy has to be absorbed and the structural integrity of the body has to be ensured in order to protect the occupants. The use of natural materials such as wood poses particular challenges for such applications. The material characteristics of wood are dispersed, and depend on environmental factors such as humidity. The aim of the following considerations was to develop a material system to ensure the functional reliability of the component. The test boundary conditions for validation also play a key role in this context. The potential of wood–steel hybrid design based on laminated veneer lumber and steel was investigated for use in a component subjected to crash loads such as the door impact beam. The chosen solution involves a separation of functions. A laminated veneer lumber-based beam was hybridized with a steel strip on the tension side. The steel strip was designed to compensate the comparatively low elongation at fracture of the wood and to ensure the integrity of the beam. The wooden component was designed for high energy absorption due to delamination and controlled failure during the impact, while maintaining the surface moment of inertia, i.e. the bending stiffness of the entire component. This approach was chosen to ensure the functional safety of the component, avoid sudden component failure and utilize the high potential of both materials. The tests carried out provided initial functional proof of the chosen solution. The hybridization achieved significantly higher deformations without sudden failure of the beam. In addition, bending capabilities were increased significantly compared to a beam without hybridization. In comparison with a state-of-the-art steel beam, the hybrid beam was not able to achieve the maximum deformation and the target weight of the hybrid beam. Further optimization of the hybrid beam is therefore necessary.

scholarly journals Suitability of Hybrid Acacia Wood for Manufacturing Plywood and Particleboard

2012 ◽  
Vol 36 (2) ◽  
pp. 171-176 ◽  
Author(s):  
MM Rahaman ◽  
K Akhter ◽  
D Biswas ◽  
MW Sheikh
Keyword(s):  
Bending Strength ◽  
Unit Area ◽  
Urea Formaldehyde ◽  
Acacia Mangium ◽  
Solid Content ◽  
Timber Species ◽  
Press Temperature ◽  
Natural Crossing ◽  
Press Time ◽  
Academy Of Sciences

Hybrid acacia, produced from natural crossing between two introduced timber species Acacia mangium and A. auriculiformies has been studied for assessing the suitability of plywood and particleboard manufacture. It was found that 1.5 mm thick smooth and figured veneer can be made and dried easily. Three-ply plywood were made using veneer of this species bonded with liquid urea formaldehyde glue of 50% solid content extended with wheat flower and catalyzed (ammonium chloride) with 2% hardener under the specific pressures, viz., 1.05, 1.40 and 1.76 N/mm2 in three replications at 6 minute press time and 120°C press temperature. Dry and wet shear test were conducted on the sample and their shear load at failure per unit area and percentage of wood failure were determined. 1.76 N/mm2 pressure for the manufacture of ply wood is found to be the best. The particleboard was tested for determining the strength and dimensional stability. The bending strength passed the standard specification, tensile strength was found to be low as per Indian standard. DOI: http://dx.doi.org/10.3329/jbas.v36i2.12960 Journal of Bangladesh Academy of Sciences, Vol. 36, No. 2, 171-176, 2012

Charring rates for double beams made from laminated veneer lumber (LVL)

2012 ◽  
Vol 37 (1) ◽  
pp. 58-74 ◽  
Author(s):  
Kevin Tsai ◽  
David Carradine ◽  
Peter Moss ◽  
Andrew Buchanan
Keyword(s):  
Laminated Veneer Lumber

Study of effect of waste tire rubber which is a recycling material in production of laminated veneer lumber (LVL) boards

2021 ◽  
pp. 147776062110194
Author(s):  
Kadir Özkaya ◽  
Taner Dizel ◽  
Hasan Özgür Imirzi
Keyword(s):  
Environmental Problem ◽  
Forest Products ◽  
Longitudinal Direction ◽  
Mechanical Tests ◽  
Pinus Silvestris ◽  
Forest Products Industry ◽  
Scotch Pine ◽  
Laminated Veneer Lumber ◽  
Waste Tire ◽  
Different Types

The amount of waste produced by people increases with the increasing population in the world. Especially non-recyclable wastes have become a major environmental problem. Waste tires that emerge as car demands of people increase are one of the non-recyclable wastes. In this study, the usage possibilities of powder rubbers obtained from waste car tires were examined in the production of laminated veneer lumber (LVL) boards, which are preferred as furniture and decoration material in the forest products industry. For this, three different tree species (Scotch Pine— Pinus silvestris L., Oriental Beech— Fagus orientalis L., Stinking Juniper— Juniperus foetidissima Wild.) and two different types of glue (UF and PVAc glues) were used. Waste tire rubbers (WTR) were mixed into the glue in different proportions (0%, 10%, 20%, 30%). Physical (full dry and equilibrium moisture density, contraction in the transversal and longitudinal direction) and mechanical tests (MoR, MoE, bonding resistance) were performed on the LVL samples prepared. According to the results obtained, it has been seen that the mixtures of 10% and 20% WTR increase the LVL resistance. An eco-friendly building material has been obtained by using WTR produced from waste car tires in production of LVL.

Sign in / Sign up

Export Citation Format

Share Document