scholarly journals Comparative Researcehs of the Properties of Laboratory Plywood and Some Industrial Manufactured Wood-Based Panels

2017 ◽  
Vol 2017 ◽  
pp. 258
Author(s):  
Violeta T Jakimovska

The aim of the researches in the master thesis is studying the impact of the changes in plywood structure on their physical and mechanical properties. These changes are related to the change of the layer’s position in the panels’ structure along the axis of symmetry without changing the number and the thickness of the veneers. Four models of laboratory nine layered plywood were made for studying this impact. The evaluation of the models quality was made on the base of the obtained values from the tests of their physical and mechanical properties, as well as on the base of the comparative analyze of these values and the values obtained from the tested properties of comparative model of industrial manufactured plywood. The laboratory plywood models are made in controlled laboratory conditions by the method of hot dry pressing. Beech peeled veneers with thickness of 1,2; 1,5; 2,2 and 3,2 mm are used for plywood manufacturing. As gluing component for plywood manufacturing, pure water-soluble phenol formaldehyde resin with concentration of 47,10 % is used. The models are preserved with phenol formaldehyde foil, which is impregnated in the surface layers during pressing. Four panels from each model are made, as well as two additional panels without surface phenol formaldehyde foil from the second model in order to perceive the differences in physical properties between preserved and non-preserved laboratory models.

2017 ◽  
Vol 2017 ◽  
pp. 258
Author(s):  
Violeta T Jakimovska

The aim of the researches in the master thesis is studying the impact of the changes in plywood structure on their physical and mechanical properties. These changes are related to the change of the layer’s position in the panels’ structure along the axis of symmetry without changing the number and the thickness of the veneers. Four models of laboratory nine layered plywood were made for studying this impact. The evaluation of the models quality was made on the base of the obtained values from the tests of their physical and mechanical properties, as well as on the base of the comparative analyze of these values and the values obtained from the tested properties of comparative model of industrial manufactured plywood. The laboratory plywood models are made in controlled laboratory conditions by the method of hot dry pressing. Beech peeled veneers with thickness of 1,2; 1,5; 2,2 and 3,2 mm are used for plywood manufacturing. As gluing component for plywood manufacturing, pure water-soluble phenol formaldehyde resin with concentration of 47,10 % is used. The models are preserved with phenol formaldehyde foil, which is impregnated in the surface layers during pressing. Four panels from each model are made, as well as two additional panels without surface phenol formaldehyde foil from the second model in order to perceive the differences in physical properties between preserved and non-preserved laboratory models.


Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 876
Author(s):  
Fan Li ◽  
Cuiyin Ye ◽  
Yanhui Huang ◽  
Xianmiao Liu ◽  
Benhua Fei

Phenol-formaldehyde (PF) resin, modified using nano-copper with varying contents (0 wt%, 1 wt%, 3 wt%), was manufactured to improve the mechanical properties of Chinese fir. The morphology, chemical, micromechanical and micromechanical properties of the samples were determined by transmission electron microscopy (TEM), atomic force microscopy (AFM), environmental scanning electron microscopy (ESEM), Fourier transform infrared spectroscopy (FTIR), nanoindentation (NI) and traditional mechanical testing. The TEM and AFM results indicated that the in situ synthesized nano-copper particles were well-dispersed, and spherical, with a diameter of about 70 nm in PF resin. From the FTIR chemical changes detected by FTIR inferred that the nano-copper modified PF resin penetrated into the Chinese fir cell walls and interacted with the acetyl groups of hemicellulose by forming a crosslinked structure. Accordingly, the micro-mechanical properties of the Chinese fir cell walls were enhanced after treatment with nano-copper modified PF resin. The filling of the PF-1-Cu resin (1 wt% nano-copper) in the wood resulted in 13.7% and 22.2% increases in the elastic modulus (MOE) and hardness, respectively, of the cell walls. Besides, the impact toughness and compressive strength of the Chinese fir impregnated with PF-1-Cu resin were 21.8% and 8.2% higher than that of the PF-0-Cu resin. Therefore, in situ synthesized nano-copper-modified PF resin is a powerful treatment method for Chinese fir due to improved diffusive properties and reinforcement of the mechanical properties.


2021 ◽  
Vol 17 (2) ◽  
pp. 152-159
Author(s):  
Rynaldo Davinsy ◽  
Sena Maulana ◽  
Muhammad I Maulana ◽  
Elvara D Satria ◽  
Deded S Nawawi ◽  
...  

Hybrid Bamboo Oriented Strand Boards (OSB) were produced to improve bamboo OSB's physical and mechanical properties. Shelling ratio adjustment of the strand type combination could determine the optimal physical and mechanical properties of hybrid bamboo oriented strand boards (OSB). The purpose of this study was to evaluate the physical and mechanical properties of hybrid betung and andong bamboos OSB at various shelling ratios. Steam modified strands of betung and andong bamboo were used as an outer layer and core layer, respectively. Hybrid bamboo OSBs were prepared with 0.7 g cm-3 target density and 8% phenol-formaldehyde resin content. Three layers of OSB were made with outer: core shelling ratios of 30:70, 40:60, 50:50, and 60:40. The physical and mechanical properties of the OSB were tested referring to the JIS A 5908-2003 standard. The targeted board density was achieved and the physical properties of all hybrid bamboo OSB have met the requirement of CSA O437.0 (Grade O-1) standard criteria. The parallel modulus of elasticity (MOE) and modulus of rupture (MOR) increased with increasing outer layer ratio. However, the perpendicular MOE and MOR decreased with increasing outer layer ratio. The internal bonding (IB) of the OSB with a shelling ratio of 30:70 and 40:60 met with the requirement of the CSA O437.0 (Grade O-1) standard.


BioResources ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 987-996
Author(s):  
Muhammad Iqbal Maulana ◽  
Rio Ardiansyah Murda ◽  
Byantara Darsan Purusatama ◽  
Rita Kartika Sari ◽  
Deded Sarip Nawawi ◽  
...  

Effects of alkali washing were determined after steam treatment of Betung bamboo strands relative to the properties of the bamboo oriented strand boards (BOSBs). The strands were subjected to steam treatment at 126 °C for 1 h under 0.14 MPa of pressure, followed by washing with sodium hydroxide solution at concentrations ranging from 1% to 5% for 30 s. Three-layer BOSBs were manufactured with a target density of approximately 0.7 g/cm3 using 8% phenol formaldehyde resin with the addition of 1% wax. The shelling ratio of the BOSBs was set to be 1:1:1. The physical and mechanical properties increased significantly with the alkali washing treatment at concentrations from 1% to 3%, and the greatest properties were obtained by washing at 3% alkali concentration. However, the washing treatment at concentrations of 4% and 5% reduced the physical and mechanical properties of the BOSBs.


2011 ◽  
Vol 217-218 ◽  
pp. 490-494
Author(s):  
Gai Yun Li ◽  
Te Fu Qin

The waste brown-rotted wood was liquefied in phenol with phosphoric acid as a catalyst and the resulting liquefied products were condensed with formaldehyde to yield novolak liquefied wood-based phenol formaldehyde resin (LWF). The results showed that brown-rotted wood could be almost completely liquefied within 0.5 h at phenol to wood (P/W) ratio 2. An increase in P/W ratio from 2 to 3 slightly improved the flow property of LWF, but accompanied by decreasing the product yield from approximately 140 to 120 %. The increase of liquefaction time from 30 min to 60 min did not have a significant influence on the resulting LWF. The thermofluidity of LWF were compared to that of the commercial novolak PF resin, and could be used to make moldings with similar thermal property and mechanical properties to those obtained from the conventional novolak PF resin.


2020 ◽  
Vol 57 (1) ◽  
pp. 28-36
Author(s):  
Vasiliy Cherkasov ◽  
Yuiy Yurkin ◽  
Valeriy Avdonin ◽  
Dmitriy Suntsov

It is actual now to work out new radiation protecting sheeting on the basis of non-curing polymeric composition which possess self-adhesion properties, are easily mounted and dismantled and provide high tightness and low permeability. Mechanical properties of non-curing composites consisting of ethylene propylene diene monomer (EPDM), industrial oil (IO), alkyl phenol-formaldehyde resin (PF) with addition of barite (52 %) to the total material volume were investigated in this article. The aim of investigation is to find optimal content of the above mentioned components at which it would be possible to get the following properties: composite would be sticky enough (peel strength not less than 4 N/cm); character of a separation would be cohesive (on a material) and thus there would be no migration of softener and satisfactory resistance of fluidity. The results showed that PF addition till 20 % in the system EPDM/PF leads to the increasing of adhesive strength, in this case optimal oil concentration in the system EPDM/PF/IO is in the interval from 45 till 55 %. New self-adhesion lead-free material, exhibited higher X-ray-shielding properties, is also received in the result of investigation.


BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 5422-5435
Author(s):  
Sena Maulana ◽  
Wahyu Hidayat ◽  
Ihak Sumardi ◽  
Nyoman J. Wistara ◽  
Muhammad I. Maulana ◽  
...  

Physical and mechanical properties were evaluated for bamboo-oriented strand boards (BOSB) prepared with combinations of two contrasting bamboo species and bonded with phenol formaldehyde resin under various compression ratios. The strands from the culms of Gigantochloa pseudoarundinacea and Dendrocalamus asper bamboo were steam-treated at a temperature of 126 °C and a pressure of 0.14 MPa for 1 h and then washed with a 1% NaOH solution. Three-layer dual-species bamboo-oriented strand boards with a shelling ratio of 25 to 50 to 25 (face to core to back) were manufactured with different compression ratios using an 8% phenol formaldehyde adhesive and 1% paraffin. The slenderness ratio and aspect ratio were evaluated by measuring 100 random strands to determine uniformity. The solidity profiles of the dual-species bamboo-oriented strand boards (thickness direction) were relatively uniform. The modulus of rupture, modulus of elasticity, and internal bond values of the dual-species bamboo-oriented strand boards increased as the compression ratio increased, but the water absorption and thickness swelling decreased. The dual-species bamboo-oriented strand boards prepared with compression ratios of 1.44 to 1.25 and 1.54 to 1.33 met all the requirements of CSA standard 0437 (2011). The optimum compression ratio for the preparation of dual-species bamboo-oriented strand boards was 1.44 to 1.25.


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