Utilization of phenol formaldehyde/Fe3O4 nanocomposite as microwave preheating amplifier in laminated veneer lumber (LVL) structure

2022 ◽  
Vol 46 ◽  
pp. 103809
Author(s):  
Mohammad Farajollah Pour ◽  
Hossein Khanjanzadeh ◽  
Ali Dorieh ◽  
Mohammad Valizadeh Kiamahalleh ◽  
Kazem Doost Hoseini
Keyword(s):  
Phenol Formaldehyde ◽  
Laminated Veneer Lumber

Synthesis of phenol formaldehyde (PF) resin for fast manufacturing laminated veneer lumber (LVL)

Holzforschung ◽  
2018 ◽  
Vol 72 (9) ◽  
pp. 745-752 ◽  
Author(s):  
Shu Hong ◽  
Zhongji Gu ◽  
Ling Chen ◽  
Ping Zhu ◽  
Hailan Lian
Keyword(s):  
Bonding Strength ◽  
Production Efficiency ◽  
Phenol Formaldehyde ◽  
Alkaline Condition ◽  
Cross Linking ◽  
Cold Pressing ◽  
Laminated Veneer Lumber ◽  
High Production Efficiency ◽  
High Production ◽  
Winter Time

AbstractPhenol formaldehyde (PF) resin is a well-tried adhesive for manufacturing laminated veneer lumber (LVL). PF has a high bonding strength, good cold pressing property and contributes a lot to the high production efficiency of LVL. In the present paper, PFs were synthesized at three different alkaline condition levels with a molar formaldehyde to phenol (F/P) ratio of 2.25. The bonding strength of PFs was not influenced by the alkalinity. Compared with PFs synthesized under alkalinity of 1 and 4%, PF with 8% alkalinity formed a resin with a high mole mass (MM), uniform mole mass distribution (MMD) and a high cross-linking density. With PF8%, the cold pressing property could be shortened from 30 to 12 min in the winter time. Cured PF8%had a higher cross-linking density than PF1%and PF4%. PF8%has a high potential for industrial production of LVL.

Modification of beech veneers with lignin phenol formaldehyde resins in the production of laminated veneer lumber (LVL)

2017 ◽  
Vol 76 (3) ◽  
pp. 843-851 ◽  
Author(s):  
Marco Fleckenstein ◽  
Vladimirs Biziks ◽  
Carsten Mai ◽  
Holger Militz
Keyword(s):  
Phenol Formaldehyde ◽  
Laminated Veneer Lumber

Manufacturer Technology of Dense Chinese Fir Laminated Veneer Lumber (LVL)

2012 ◽  
Vol 542-543 ◽  
pp. 363-366
Author(s):  
Chi Qiang Yao ◽  
Li Yu ◽  
Yan Jun Li ◽  
Shi Ke Xu ◽  
Lan Xing Du
Keyword(s):  
Mechanical Properties ◽  
Hot Pressing ◽  
Phenol Formaldehyde ◽  
Chinese Fir ◽  
Water Soluble ◽  
Technological Parameters ◽  
Pressing Temperature ◽  
Laminated Veneer Lumber ◽  
Pressing Time ◽  
Processing Factors

Dense Chinese Fir LVL was manufactured from Chinese Fir veneer which was impregnated with laboratory prepared water soluble phenol formaldehyde(PF) resin. The influences of various processing factors on properties of dense Chinese Fir LVL were explored. It is showed that the mechanical properties of dense Chinese Fir LVL first increase and then decrease with the increase of drying temperature and hot-pressing time. Plank performance becomes higher with the increase of compressibility and hot-pressing temperature. The optimum technological parameters for LVL process are set.

Reinforcement of Laminated Veneer Lumber with Ramie Fibre

2011 ◽  
Vol 332-334 ◽  
pp. 41-44 ◽  
Author(s):  
Zhi Qiang Wang ◽  
Xiao Ning Lu ◽  
Xiao Juan Huang
Keyword(s):  
Phenol Formaldehyde ◽  
Fibre Composite ◽  
Phase 1 ◽  
Preliminary Investigation ◽  
Modulus Of Rupture ◽  
Control Group ◽  
Laminated Veneer Lumber ◽  
Loading Direction ◽  
Two Phases ◽  
Wood Based Composite

This paper describes a preliminary investigation on the use of ramie fibre/ phenol formaldehyde (PF) composite to reinforce laminated veneer lumber (LVL). This research was conducted in two phases. Phase 1 the ramie fibre was treated with KH-550 silane coupling agent. Phase 2 different numbers of sheets ramie fibre/PF were added in different location of LVL to reinforce. The reinforced LVL was hot pressed at one time. A control group of unreinforced LVL was also manufactured. The results showed that the improvement in level shear properties of reinforced LVL was obvious no matter what loading direction was perpendicular or parallel. The improvement in modulus of elasticity (MOE) and modulus of rupture (MOR) of partial reinforced LVL was obvious too. Preliminary results showed that using ramie fibre composite to reinforce LVL was possible. This research will further broaden the application field of natural fibres, and provide a new improvement way for wood based composite.

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

2019 ◽  
Vol 6 (12) ◽  
pp. 191763 ◽  
Author(s):  
P. S. Khoo ◽  
K. L. Chin ◽  
P. S. H'ng ◽  
E. S. Bakar ◽  
C. L. Lee ◽  
...  
Keyword(s):  
Phenol Formaldehyde ◽  
Small Diameter ◽  
Lower Grade ◽  
Bonding Quality ◽  
Laminated Veneer Lumber ◽  
Short Rotation ◽  
Different Temperatures ◽  
Lamination Process ◽  
Lathe Check

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.

scholarly journals The effects of wood species, load direction, and adhesives on bending properties of laminated veneer lumber

BioResources ◽  
2012 ◽  
Vol 7 (3) ◽  
pp. 3104-3112 ◽  
Author(s):  
Bekir Cihad Bal ◽  
İbrahim Bektaş
Keyword(s):  
Modulus Of Elasticity ◽  
Bending Strength ◽  
Phenol Formaldehyde ◽  
Urea Formaldehyde ◽  
Eucalyptus Grandis ◽  
Variance Analysis ◽  
Modulus Of Rupture ◽  
Bending Properties ◽  
Laminated Veneer Lumber ◽  
Specific Modulus

In this study, the bending strength and stiffness of laminated veneer lumber (LVL) produced from beech (Fagus orientalis L.), poplar (Populus x euramericana I-214), and eucalyptus (Eucalyptus grandis W. Hill ex Maiden) wood using urea formaldehyde (UF), melamine urea formaldehyde (MUF), and phenol formaldehyde (PF) adhesives were determined. The tests were conducted in the flatwise and edgewise directions. The modulus of rupture (MOR), modulus of elasticity (MOE), specific modulus of rupture (SMOR), and specific modulus of elasticity (SMOE) were calculated. Variance analysis of the bending properties indicated that the effects of the species of tree, the direction of the load, and the type of adhesive were statistically significant. However, according to variance analysis of the SMOR, the effects of the type of adhesive were not significant. The results showed that the type of adhesive did not influence the bending properties of laminated veneer lumber. It can be stated that the differences among groups were due to differences in their densities. The direction of the load and the species of the tree had significant effects on the bending properties.

scholarly journals Mechanical Properties Assessment of Laminated Veneer Lumber from Teak Plantation in Laos

2021 ◽  
Vol 18 (2) ◽  
Author(s):  
Khonethong SOUKPHAXAY ◽  
Khamtan PHONETIP ◽  
Latsamy BOUPHA ◽  
Lothim SAETERN ◽  
Khanxay KHAMMANIVONG ◽  
...  
Keyword(s):  
Phenol Formaldehyde ◽  
Phenol Formaldehyde Resin ◽  
Modulus Of Rupture ◽  
Bending Test ◽  
Formaldehyde Resin ◽  
Test Results ◽  
Forest Plantation ◽  
Machine Model ◽  
Laminated Veneer Lumber ◽  
Teak Plantation

The objective of this study was to investigate the most influenced levels of pressure and length of time on modulus of rupture (MOR) and modulus of elasticity (MOE) of teak laminated veneer lumber (LVL). Teak LVL was taken from the Faculty of Forestry’s forest plantation in Vientiane, Laos. The peeled veneer’s thickness was 2.3 mm. The veneer was air-dried until the moisture content reached the range of 6 to 10 %. Teak LVL panels were assembled from 9-ply panels of veneer using PL116- Liquid phenol-formaldehyde resin adhesive. The temperature was at 120 °C at 3 different pressure levels i.e., 1.5, 2 and 2.5 MPa and levels of time i.e. 9, 11 and 13 min. The experiment was conducted based on ISO16978. Intron Machine Model 5569 was used for the bending test of LVL with a dimension of 20×20×360 mm3. The bending test results on teak LVL showed significantly different MOR and MOE based on length of time and pressure levels of pressing.

The influence of lathe check depth and orientation on the bond quality of phenol-formaldehyde – bonded birch plywood

Holzforschung ◽  
2013 ◽  
Vol 67 (7) ◽  
pp. 779-786 ◽  
Author(s):  
Anti Rohumaa ◽  
Christopher G. Hunt ◽  
Mark Hughes ◽  
Charles R. Frihart ◽  
Janne Logren
Keyword(s):  
Shear Strength ◽  
Betula Pendula ◽  
Phenol Formaldehyde ◽  
Adhesive Bond ◽  
Wood Failure ◽  
Bond Quality ◽  
Laminated Veneer Lumber ◽  
Lathe Check

Abstract During the rotary peeling of veneer for plywood or the laminated veneer lumber manufacture, checks are formed in the veneer that are as deep as 70–80% of the veneer thickness. The results of this study show that, during adhesive bond testing, deep lathe checks in birch (Betula pendula Roth.) veneer significantly reduce the shear strength and the percent wood failure of phenol-formaldehyde (PF) – bonded plywood. The results also show that specimens tested with the checks pulled open or closed can fail by different mechanisms. Dried rotary peeled birch veneers were sanded to create uniform surfaces with lathe check depths varying from 30% to 90% of veneer thickness. Then, 7-ply plywood was manufactured with a commercial PF resin. After the preparation of the test specimens, the check depth of each specimen was measured microscopically. Subsequently, bond quality was measured according to EN 314. The results show that veneer checking alone can bring EN 314 specimens to the brink of failure even with an excellent adhesive. These findings stress the importance of measuring the depth of lathe checks and considering the orientations of checks during the testing to get a better understanding of bond quality in veneer-based products.

Study on the Effect of Impregnation Process on Physical and Mechanical Properties of Chinese Fir LVL

2013 ◽  
Vol 753-755 ◽  
pp. 848-852
Author(s):  
Yu Cheng Shen ◽  
Li Ping Yin ◽  
Cheng Jian Huang ◽  
Chi Qiang Yao ◽  
Li Yu ◽  
...  
Keyword(s):  
Weight Gain ◽  
Phenol Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Chinese Fir ◽  
Water Soluble ◽  
Low Molecular Weight ◽  
Laminated Veneer Lumber ◽  
Mechanical And Physical Properties ◽  
Wet Weight ◽  
Temperature And Pressure

Laminated veneer lumber (LVL) was manufactured from Chinese fir, which had been impregnated with laboratory prepared low-molecular-weight water-soluble phenol formaldehyde (PF) resin. The effects on the mechanical and physical properties of the LVL were investigated which made from veneer that had been subjected to various levels of the resin treatment. The results showed that either under conditions of normal temperature and pressure, or at increased pressure, the weight gain would increase with the impregnating time. Under the same impregnation technology, along with the increase of resin concentration, dry weigh gain increased, wet weight gain first increased and then decreased. Density of LVL increased, TS reduced, MOR and MOE first increased and then decreased as the weight gain increased.

Sign in / Sign up

Export Citation Format

Share Document