Influence of veneer thickness on the properties of LVL from Paricá (Schizolobium amazonicum) plantation trees

Melo, Rafael Rodolfo de; Menezzi, Cláudio Henrique Soares Del

doi:10.1007/s00107-013-0770-8

Cited by 32 publications

(13 citation statements)

References 8 publications

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“…The strength properties of the product along with its dimensional stability are required in such sectors. Several factors have major influence on the mechanical properties of plywood, especially on the bending strength (MOR) and modulus of elasticity (MOE), namely wood species, density, structure, moisture content, number of veneer layers, and type of adhesive and its spreading [2][3][4][5][6][7]. Various modification methods can be used to improve the properties of such products, the thermo-mechanical densification at elevated temperatures of solid wood is one of these methods [8][9][10].…”

Section: Introductionmentioning

confidence: 99%

The Effect of Veneer Densification Temperature and Wood Species on the Plywood Properties Made from Alternate Layers of Densified and Non-Densified Veneers

Salca

Bekhta

Seblii

2020

Forests

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In this study the properties of plywood manufactured from densified and non-densified veneer sheets and alternate layers of such veneers with and without densification using low amount of adhesive as a function of densification temperature and wood species were investigated. The plywood panels were made from rotary-cut birch and black alder veneers using urea-formaldehyde (UF) adhesive. Veneer sheets with thickness of 1.5 mm were subjected to the thermal-compression at three different temperatures while keeping constant the pressure during a same time span. Five-layers plywood panels were produced using a constant hot-pressing schedule using different amounts of glue spread as a function of the plywood type; such as plywood made from non-densified (80 g/m2) and densified (60 g/m2) veneers only; and combination of them (70 g/m2). The bending strength (MOR) and the modulus of elasticity (MOE) along with the shear strength of the plywood samples for bonding class 1 (dry conditions) have been determined. As expected bending strength of the plywood samples increased with the increasing in density. The increase of veneer densification temperature resulted in a gradually decrease of MOR; MOE and shear strength values for the plywood panels made of densified veneers and mixed panels of both species. The temperature of 150 °C for veneer densification seemed to be enough to achieve enhanced bending and bonding properties. All plywood panels in this study were manufactured using reduced glue consumption and they presented satisfactory properties performance for indoor applications.

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Section: Introductionmentioning

confidence: 99%

The Effect of Veneer Densification Temperature and Wood Species on the Plywood Properties Made from Alternate Layers of Densified and Non-Densified Veneers

Salca

Bekhta

Seblii

2020

Forests

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“…In comparison with conventional solid wood products, plywood has various advantages: increased dimensional stability, uniformity and higher mechanical strength, reduced processing cost, availability in larger sizes, better appearance, and biological benefits. On the other hand, one of the main disadvantages of plywood products is using a large amount of adhesive during its manufacture, which can be up to 20% of its total mass [1]. This disadvantage decreases the plywood product’s ecological balance and makes it less favorable than solid wood, especially when considering resins derived from petrochemical resources.…”

Section: Introductionmentioning

confidence: 99%

Environmentally-Friendly High-Density Polyethylene-Bonded Plywood Panels

Bekhta

Sedliacik

2019

Polymers

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Thermoplastic films exhibit good potential to be used as adhesives for the production of veneer-based composites. This work presents the first effort to develop and evaluate composites based on alder veneers and high-density polyethylene (HDPE) film. The effects of hot-pressing temperature (140, 160, and 180 °C), hot-pressing pressure (0.8, 1.2, and 1.6 MPa), hot-pressing time (1, 2, 3, and 5 min), and type of adhesives on the physical and mechanical properties of alder plywood panels were investigated. The effects of these variables on the core-layer temperature during the hot pressing of multiplywood panels using various adhesives were also studied. Three types of adhesives were used: urea–formaldehyde (UF), phenol–formaldehyde (PF), and HDPE film. UF and PF adhesives were used for the comparison. The findings of this work indicate that formaldehyde-free HDPE film adhesive gave values of mechanical properties of alder plywood panels that are comparable to those obtained with traditional UF and PF adhesives, even though the adhesive dosage and pressing pressure were lower than when UF and PF adhesives were used. The obtained bonding strength values of HDPE-bonded alder plywood panels ranged from 0.74 to 2.38 MPa and met the European Standard EN 314-2 for Class 1 plywood. The optimum conditions for the bonding of HDPE plywood were 160 °C, 0.8 MPa, and 3 min.

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“…The mechanical properties of LVL can be affected by several factors such as juvenile wood [4,5], jointing method [6], lathe checks [7,8], load direction [9,10], veneer thickness [11] or sylvicultural pratice [12].…”

Section: Introductionmentioning

confidence: 99%

An innovative method based on grain angle measurement to sort veneer and predict mechanical properties of beech laminated veneer lumber

Viguier

Bourgeay

Rohumaa

et al. 2018

Construction and Building Materials

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This study proposes an innovative model based on local grain angle measurements to predict the modulus of elasticity of LVL made from beech. It includes a veneers sorting method industrially compatible thanks to its low computational time. For this study 41 LVL panels were prepared from 123 beech sheets of veneers. Local grain angle was obtained with a two dimensional scanner and veneer density was measured. Several models based on these measurements have been developed and their ability to predict the modulus of elasticity of LVL panels have been compared. The model based only on local grain angle measurements have been proven more efficient than models taking into account the veneer density. The proposed method can be used to sort veneer during the peeling process and grade the production of LVL panels to optimize their mechanical properties even for low-quality veneer.

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Influence of veneer thickness on the properties of LVL from Paricá (Schizolobium amazonicum) plantation trees

Cited by 32 publications

References 8 publications

The Effect of Veneer Densification Temperature and Wood Species on the Plywood Properties Made from Alternate Layers of Densified and Non-Densified Veneers

The Effect of Veneer Densification Temperature and Wood Species on the Plywood Properties Made from Alternate Layers of Densified and Non-Densified Veneers

Environmentally-Friendly High-Density Polyethylene-Bonded Plywood Panels

An innovative method based on grain angle measurement to sort veneer and predict mechanical properties of beech laminated veneer lumber

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