Addition of Boron Based Compound in the LVL Glueline: Effect on the Mechanical Properties and the Leaching of Boron

Holzforschung ◽  
2001 ◽  
Vol 55 (5) ◽  
pp. 559-562 ◽  
Author(s):  
V. Bridaux ◽  
B. Charrier ◽  
N. Fauroux ◽  
F. Charrier ◽  
J. Goncalez

Summary This study aims at the optimization of the durability of Laminated Veneer Lumber (LVL) panels by adding borates to the gluing formulation. Poplar veneers measuring 2.6 mm thickness were used for the manufacture of LVL by Isoroy, a French company located in Lisieux. The melamine-urea-formaldehyde (M.U.F.) glue formulations were mixed with various concentrations of boric acid. A 0.8% retention of boron was measured in the LVL panel after intensive water leaching. The mechanical properties of finished LVL panels and their bonding strength properties were evaluated. The influence of the glue bonding on leaching was also evaluated. The amount of boron in LVL was measured by spectrocolorimetry using the CIELAB system. Results demonstrated that the incorporation of boron in the glueline may improve LVL durability.

2019 ◽  
Vol 275 ◽  
pp. 01013
Author(s):  
Qian He ◽  
Tianyi Zhan ◽  
Haiyang Zhang ◽  
Zehui Ju ◽  
Lu Hong ◽  
...  

High voltage electrostatic field (HVEF) was applied in order to improve wood surface characteristics, bonding and mechanical properties of wood composites. Masson pine (Pinus massoniana Lamp.) plywood and laminated veneer lumber (LVL) were selected in this study. Surface characteristics were conducted by the electron spin resonance (ESR) and X-ray photoelectron spectra (XPS). Bonding interphase and mechanical properties were investigated by fluorescence microscopy and vertical density profile (VDP), bonding strength, wood failure ratio, MOE and MOR. The results indicated that more increments were obtained in free radicals, O/C ratios and C2-C4 components. This is because electrons broke more wood chemical groups and new ions occurred among wood surface under HVEF. Significantly decreased PF adhesive penetration depth (PD) and increased density at bonding interphase was achieved in HVEF treated composites. More decrease of PD and increment of density were observed in plywood than that of LVL. This was attributed to cross linked wood fibers among bonding interphase in plywood. Mechanical properties of bonding strength, wood failure ratio, MOE and MOR were significantly increased under HVEF treatment both for two composites. Higher bonding strength, MOE and MOR were obtained in plywood and their increments were as 98.53%, 33.33%, 18.55% and 12.72%.


2011 ◽  
Vol 341-342 ◽  
pp. 80-84 ◽  
Author(s):  
Yu Bo Chai ◽  
Jun Liang Liu ◽  
Xing Zhen

In order to improve the dimensional stability, mechanical properties and fire resistance of the wood from Cryptomeria fortunei, the melamine-urea-formaldehyde (MUF) resin and the mixture of MUF/boric acid/borax (MBB) were prepared and used as the wood modification solution. Results show that both the MUF resin and the MBB solutions exhibit good permeability to wood. Under the same treatment conditions, the weight percent gains (WPG) of treated wood increases with the increasing concentration of modification solutions. MUF and MBB modification solutions can effectively enhance the dimensional stability, MOR, MOE and fire resistance of wood. Compared with MBB treated wood, MUF treated wood exhibits higher MOR and dimensional stability. The MBB treated wood has higher MOE and fire resistance than MUF treated wood.


2021 ◽  
Vol 2129 (1) ◽  
pp. 012001
Author(s):  
K C Liew ◽  
A R Samin

Abstract The purpose of this study was to evaluate the mechanical properties of particleboards made from Acacia mangium wood particles binded with three different types of seaweed-based adhesive. Red seaweed (RS), brown seaweed (BS) and green seaweed (GS) were used as the seaweed-based adhesives., while particleboard using urea formaldehyde (UF) adhesive was produced as control. Adhesives and wood particles were mixed and then undergone mat-forming, pre-pressing, hot-pressing and conditioning process. The test pieces for bending test (Modulus of Elasticity, MOE; Modulus of Rupture, MOR), and internal bonding strength (IB) were cut into size according to JIS A 5908: 2003. From mechanical properties results attained, for internal bonding strength test, all boards using RS, BS and GS adhesives were found to be significantly different at p≤0.05. Apart from that, RS adhesive showed highest MOE and MOR at 529.4259 N/mm2 and 1.7900 N/mm2, respectively. As a conclusion, the mechanical properties of particleboard using RS, BS, and GS adhesives showed RS stands out as the better adhesive among them which have significant effects on its strength.


2020 ◽  
Vol 25 (4) ◽  
pp. 657-663
Author(s):  
Achmad Supriadi ◽  
Deazy Rachmi Trisatya ◽  
Ignasia Maria Sulastiningsih

The objective of this study was to determine the physical and mechanical properties of plywood made of punak (Tetramerista glabra Miq.), meranti bunga (Shorea teysmanniana Dyer ex Brandis), mempisang (Alphonsea spp.), suntai (Palaqium burckii H.J.L.), and pasak linggo (Aglaia argentea Blume). Liquid urea formaldehyde (UF) was used as an adhesive. Data analysis was carried out using a completely randomized design. Results showed that the moisture content and density of plywood produced in this study were around 10.4-10.95% and 0.65 to 0.93 g/cm3, respectively. The modulus of elasticity (MOE) and modulus of rupture (MOR) of plywood produced were between 63.371-123.548 kg/cm2 and 517-1.052 kg/cm2, respectively. It was also found that the tensile strength and bonding strength of the plywood produced were 461.6-1.095 kg/cm2 and 18.97-31.79 kg/cm2, respectively. It was recorded that moisture content and the bonding strength of the plywood produced met the Indonesian National Standard of Plywood. Among others, plywood produced from pasak linggo showed a superior quality. Referring to statistical analysis, it was confirmed that physical and mechanical properties of plywood were significantly affected by wood species, except moisture content. Keywords: mechanical properties, physical properties, plywood, Riau wood species


2021 ◽  
Vol 899 ◽  
pp. 86-91
Author(s):  
Victor Klushin ◽  
Denis Tokarev ◽  
Vera Kashparova ◽  
Svetlana Kolesnik ◽  
Ivan Brink

In the present work, composite materials with a two wastes - waste goose feather as a filler and resinous waste from HMF production as a binder - have been developed. The mechanical properties and water sorption in dependence with feather/HMF resin composite content were studied. The composites containing 50% of feather have high strength properties up to 46 N/mm2 and low water sorption (lower 1%), which results in high water resistance. Due to these properties, they can become an excellent alternative to urea-formaldehyde resins and plastics based on them.


2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Zenat A. Nagieb ◽  
Mona A. Nassar ◽  
Magda G. El-Meligy

Properties of the flame retardant urea formaldehyde (UF) board made from saw dust fibers were investigated. Flame retardant chemicals that were evaluated include boric acid (BA) and borax (BX) which were incorporated with saw dust fibers to manufacture experimental panels. Three concentration levels, (0.5, 1, and 5%) of fire retardants and 10% urea formaldehyde resin based on oven dry fiber weight were used to manufacture experimental panels. Physical and mechanical properties including water absorption, modulus of rupture (MOR), and modulus of elasticity (MOE) were determined. The results showed that water absorption and bending strength decreased as the flame retardant increased. The highest concentration of (BA + BX) enhanced the fire retardant more than the lower ones. Scanning electron microscope and FTIR of composite panels were studied.


2020 ◽  
pp. 313-317
Author(s):  
A.I. Kovtunov ◽  
Yu.Yu. Khokhlov ◽  
S.V. Myamin

Titanium—aluminum, titanium—foam aluminum composites and bimetals obtained by liquid-phase methods, are increasingly used in industry. At the liquid-phase methods as result of the reaction diffusion of titanium and aluminum is formed transitional intermetallic layer at the phase boundary of the composite, which reduces the mechanical properties of titanium and composite. To reduce the growth rate of the intermetallic layer between the layers of the composite and increase its mechanical properties, it is proposed to alloy aluminum melt with nickel. The studies of the interaction of titanium and molten aluminum alloyed with nickel made it possible to establish the effect of temperature and aluminizing time on the thickness, chemical and phase compositions of the transition intermetallic layer. The tests showed the effect of the temperature of the aluminum melt, the nickel concentration on the strength properties of titanium—aluminum bimetal.


2021 ◽  
Vol 13 (15) ◽  
pp. 8164
Author(s):  
Brian E. Bautista ◽  
Lessandro E. O. Garciano ◽  
Luis F. Lopez

There are limited published studies related to the mechanical properties of bamboo species in the Philippines. In this study, the shear strength properties of some economically viable bamboo species in the Philippines were properly characterized based on 220 shear test results. The rationales of selecting this mechanical property are the following: (1) Shear strength, parallel to the fiber, has the highest variability among the mechanical properties; and (2) Shear is one of the governing forces on joint connections, and such connections are the points of failure on bamboo structures when subjected to extreme loading conditions. ISO 22157-1 (2017) test protocol for shear was used for all tests. The results showed that Bambusa blumeana has the highest average shear strength, followed by Gigantochloa apus, Dendrocalamus asper, Bambusa philippinensis, and Bambusa vulgaris. However, comparative analysis, using One-way ANOVA, showed that shear strength values among these bamboo species have significant differences statistically. A linear regression model is also established to estimate the shear strength of bamboo from the physical properties. Characteristic shear strength is also determined using ISO 12122-1 (2014) for future design reference.


2020 ◽  
Vol 5 (1) ◽  
pp. 711-725
Author(s):  
Sutrisno ◽  
Eka Mulya Alamsyah ◽  
Ginanjar Gumilar ◽  
Takashi Tanaka ◽  
Masaaki Yamada

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.


Sign in / Sign up

Export Citation Format

Share Document