scholarly journals Particle Board and Oriented Strand Board Prepared with Nanocellulose-Reinforced Adhesive

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Stefan Veigel ◽  
Jörn Rathke ◽  
Martin Weigl ◽  
Wolfgang Gindl-Altmutter
Keyword(s):  
Bending Strength ◽  
Oriented Strand Board ◽  
Urea Formaldehyde ◽  
Cellulose Nanofibers ◽  
Strength Properties ◽  
Particle Board ◽  
Adhesive Bonds ◽  
Adhesive Mixtures ◽  
Scale Particle ◽  
Muf Adhesives

Adhesives on the basis of urea-formaldehyde (UF) and melamine-urea-formaldehyde (MUF) are extensively used in the production of wood-based panels. In the present study, the attempt was made to improve the mechanical board properties by reinforcing these adhesives with cellulose nanofibers (CNFs). The latter were produced from dissolving grade beech pulp by a mechanical homogenization process. Adhesive mixtures with a CNF content of 0, 1, and 3 wt% based on solid resin were prepared by mixing an aqueous CNF suspension with UF and MUF adhesives. Laboratory-scale particle boards and oriented strand boards (OSBs) were produced, and the mechanical and fracture mechanical properties were investigated. Particle boards prepared with UF containing 1 wt% CNF showed a reduced thickness swelling and better internal bond and bending strength than boards produced with pure UF. The reinforcing effect of CNF was even more obvious for OSB where a significant improvement of strength properties of 16% was found. For both, particle board and OSB, mode I fracture energy and fracture toughness were the parameters with the greatest improvement indicating that the adhesive bonds were markedly toughened by the CNF addition.

scholarly journals Utilization of Partially Liquefied Bark for Production of Particleboards

2020 ◽  
Vol 10 (15) ◽  
pp. 5253 ◽  
Author(s):  
Wen Jiang ◽  
Stergios Adamopoulos ◽  
Reza Hosseinpourpia ◽  
Jure Žigon ◽  
Marko Petrič ◽  
...  
Keyword(s):  
Bending Strength ◽  
Urea Formaldehyde ◽  
Value Added ◽  
Thickness Swelling ◽  
Mechanical And Physical Properties ◽  
Dry Conditions ◽  
Synthetic Adhesives ◽  
European Standards ◽  
Muf Adhesives

Bark as a sawmilling residue can be used for producing value-added chemicals and materials. This study investigated the use of partially liquefied bark (PLB) for producing particleboard with or without synthetic adhesives. Maritime pine (Pinus pinaster Ait.) bark was partially liquefied in the presence of ethylene glycol and sulfuric acid. Four types of particleboard panels were prepared with a PLB content of 4.7%, 9.1%, 20%, and 33.3%, respectively. Another five types of particleboard panels were manufactured by using similar amounts of PLB and 10 wt.% of melamine–urea–formaldehyde (MUF) adhesives. Characterization of bark and solid residues of PLB was performed by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and automated vapor sorption (AVS). Mechanical and physical properties of the particleboard were tested according to the European standards EN 310 for determining modulus of elasticity and bending strength, EN 317 for determining thickness swelling after immersion in water, and EN 319 for determining internal bond strength. The results showed that the increase in PLB content improved the mechanical strength for the non-MUF boards, and the MUF-bonded boards with up to 20% of PLB met the requirements for interior uses in dry conditions according to EN 312. The non-MUF boards containing 33.3% of PLB and the MUF-bonded boards showed comparable thickness swelling and water absorption levels compared to the reference board.

Peeling and Gluing Study of Khaya anthotheca for Ply and Particle Board

2015 ◽  
Vol 38 (2) ◽  
pp. 113-116
Author(s):  
Md. Rahaman ◽  
Khurshid Akhter ◽  
Md. Islam
Keyword(s):  
Bending Strength ◽  
Unit Area ◽  
Urea Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Solid Content ◽  
Shear Load ◽  
Particle Board ◽  
British Standard ◽  
Press Temperature ◽  
Press Time

Logs of Khaya anthotheca wood 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 flour and catalyzed (ammonium chloride) with 2% hardener under the specific pressures, viz, 1.05 N/mm2, 1.40 N/mm2, 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. 1.05 N/mm2 pressure for the manufacture of ply wood was found to be the best. The physical and mechanical properties of K.anthotheca particleboard were studied. The particleboards were tested for determining the strength and dimensional stability. The tensile strength (internal bond strength 0.68 N/mm2) passed the German and British standard specifications; bending strength (modules of rupture 11.25 N/mm2) passed the Indian Standard but did not pass the German and British standard specifications.

Understanding the thermal durability of wood-based composites (WBCs) using crack propagation fracture toughness

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sweta Mahapatra ◽  
Arijit Sinha ◽  
John A. Nairn
Keyword(s):  
Fracture Toughness ◽  
Crack Propagation ◽  
Bending Strength ◽  
Oriented Strand Board ◽  
Medium Density Fiberboard ◽  
Strength Properties ◽  
Wood Products ◽  
Trilinear Model ◽  
Different Temperatures

Abstract Wood-based composites (WBCs) are engineered wood products that are commonly used in the building and furniture industries. Most research on their durability has relied on internal bond testing, bending strength properties, or damage observations. An alternative property with potentially more information is fracture toughness. Here, fracture toughness was continuously measured during crack propagation for three different composites—oriented strand board (OSB), medium density fiberboard (MDF), and particleboard (PB). The resulting plots for fracture toughness as a function of crack growth are known as the material’s R curve. To assess the role of temperature on WBC durability, R curve experiments were repeated at 10 different temperatures from 20 to 200 °C. Trends in experimental results could be described by a trilinear model. OSB and MDF toughness initially increased with temperature and then decreased above 80 °C. The toughness of PB, which was made with a different resin, remained constant or decreased slightly until decreasing faster above 140 °C. Both the resin type and composite structure affected the results.

scholarly journals Functionality of Beech Bark in Adhesive Mixtures Used in Plywood and Its Effect on the Stability Associated with Material Systems

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1298 ◽  
Author(s):  
Roman Réh ◽  
Rastislav Igaz ◽  
Ľuboš Krišťák ◽  
Ivan Ružiak ◽  
Milada Gajtanska ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Urea Formaldehyde ◽  
Wood Processing ◽  
Material Systems ◽  
Adhesive Mixtures ◽  
The Common ◽  
The Stability ◽  
Heating Up

The results of research into utilizing grinded beech bark in order to substitute commonly used fillers in urea formaldehyde (UF) adhesive mixtures to bond plywood are presented in the present study. Four test groups of plywood with various adhesive mixtures were manufactured under laboratory conditions and used for experimentation. Plywood made using the same technology, with the common filler (technical flour), was used as a reference material. Three different concentrations of grinded beech bark were used. The thermal conductivity of the fillers used, viscosity and its time dependence, homogeneity and the dispersion performance of fillers were evaluated in the analysis of adhesive mixture. The time necessary for heating up the material during the pressing process was a further tested parameter. The produced plywood was analyzed in terms of its modulus of elasticity, bending strength, perpendicular tensile strength and free formaldehyde emissions. Following the research results, beech bark can be characterized as an ecologically friendly alternative to technical flour, shortening the time of pressing by up to 27%. At the same time, in terms of the statistics, the mechanical properties and stability of the material changed insignificantly, and the formaldehyde emissions reduced significantly, by up to 74%. The utilization of bark was in compliance with long-term sustainability, resulting in a decrease in the environmental impact of waste generated during the wood processing.

scholarly journals Biological Resistance and Application Properties of Particleboards Containing Nano-Zinc Oxide

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Ladislav Reinprecht ◽  
Ján Iždinský ◽  
Zuzana Vidholdová
Keyword(s):  
Zinc Oxide ◽  
Bending Strength ◽  
Urea Formaldehyde ◽  
Brown Rot ◽  
Strength Properties ◽  
Nano Zno ◽  
Biological Resistance ◽  
Weight Losses ◽  
Nano Zinc Oxide ◽  
Nano Zinc

Special particleboards (PBs) proposed for kitchens, bathrooms, hospitals, and some other specific products for interiors should have a sufficient resistance against bacteria, molds, and decaying fungi. This work deals about effects of zinc oxide nanoparticles (nano-ZnO) added into melamine-urea-formaldehyde (MUF) glue in the amounts of 0, 2, 6, 12, or 24% wt. on selected biological, moisture, and strength properties of laboratory-produced one-layer PBs. The nano-ZnO-treated PBs had a higher biological resistance: (1) against the Gram-positive bacterium Staphylococcus aureus by up to ca. 70% and the Gram-negative bacterium Escherichia coli by up to 50%, since their bacterial activities at using 1.0 McFarland bacterial inoculum decreased from 0.38–0.40 by up to 0.12–0.19  ×  108 CFU/ml; (2) against the molds Penicillium brevicompactum and Aspergillus niger by up to ca. 50–63%, since their growth intensities (0–4) on the top surfaces of treated PBs decreased according to a modified EN 15457 from 2.33–2.67 by up to 1.17–1.0; (3) against the brown-rot fungus Coniophora puteana by up to 85.7%, since their weight losses reduced according to a modified ENV 12038 from 17.4% by up to 2.5%. The presence of nano-ZnO in PBs uninfluenced their swelling, water absorption, and bending strength; however, it decreased their internal bond strength by up to 38.8%.

scholarly journals Possibility of Use of NCC-Reinforced Melamine-Urea- Formaldehyde Adhesive in Plywood Manufacturing

2021 ◽  
Vol 72 (3) ◽  
pp. 279-289
Author(s):  
Jakub Kawalerczyk ◽  
Dorota Dziurka ◽  
Radosław Mirski ◽  
Joanna Siuda ◽  
Marta Babicka
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Fourier Transform Infrared Spectroscopy ◽  
Modulus Of Elasticity ◽  
Bending Strength ◽  
Urea Formaldehyde ◽  
Fourier Transform Infrared ◽  
Bonding Quality ◽  
Adhesive Mixtures

The possibility of using nanocellulose (NCC) as a filling substance for melamine-urea-formaldehyde (MUF) adhesive was investigated for the process of manufacturing plywood. The adhesive mixtures were prepared with various nanocellulose concentrations. The amount of introduced filler had a significant effect on both resin and plywood characteristics. Fourier transform infrared spectroscopy (FTIR) did not show any major changes between experimental and reference variants. The viscosity of resin increased after the introduction of nanocellulose. The addition of NCC in the amount of 5 g and 10 g per 100 g of solid resin led to an improvement in bonding quality, modulus of elasticity and bending strength. Further increase of NCC concentration caused a deterioration of manufactured plywood properties. In summary, the addition of proper amount of nanocellulose resulted in manufacturing plywood with improved properties.

scholarly journals Analysis of low requirement justification of the current standard for the strength of wood particle boards

2021 ◽  
Vol 875 (1) ◽  
pp. 012068
Author(s):  
E M Razinkov ◽  
T L Ishchenko
Keyword(s):  
State Standard ◽  
Bending Strength ◽  
Wood Particle ◽  
Strength Properties ◽  
State Standards ◽  
Particle Board ◽  
Current Standard ◽  
Permissible Level ◽  
Technical Requirements ◽  
Low Strength

Abstract Currently, wood particle boards made of crushed shavings are widely used in the production of cabinet furniture, despite their shortcomings. The volume of particle board production in Russia is constantly growing. The main disadvantages of the boards include their toxicity associated with the release of gas (formaldehyde) harmful to humans above the permissible level (PL = 0.01 mg/m3 of air), low strength properties (especially bending strength) and limited areas of application of the boards. If we trace the dynamics of the technical requirements for these properties of boards according to the standards, then the question arises - what is the reason for the decrease in the requirements for the strength of boards in bending and, in this regard, the limitation of the application areas of particle board? A regular decrease in the requirements in the newly introduced State Standards has been constantly occurring since 1977, but this is especially noticeable in the current 10632-2014 State Standard. This article focuses on the possible objective and subjective reasons for the low requirements of the current standard for the strength of wood particle board.

scholarly journals Density, hardness and strength properties of densified fir and aspen woods pretreated with water repellents

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Hüseyin Pelit ◽  
Fatih Emiroglu
Keyword(s):  
Compression Ratio ◽  
Bending Strength ◽  
Linseed Oil ◽  
Vacuum Treatment ◽  
Strength Properties ◽  
Aspen Wood ◽  
Positive Effect ◽  
Water Repellents ◽  
Impregnated Wood ◽  
Compression Temperature

AbstractIn this study, the effect of thermo-mechanical densification on the density, hardness, compression strength, bending strength (MOR), and modulus of elasticity (MOE) of fir and aspen wood pretreated with water repellents was analyzed. Wood specimens were impregnated with paraffin, linseed oil and styrene after pre-vacuum treatment. Then, the impregnated wood specimens were densified with compression ratios of 20 and 40%, and at 120, 150 and 180 °C. The results indicated that the density, hardness and strength properties of the all densified specimens (untreated and impregnated) increased depending on the compression ratio and temperature. For all tested properties, higher increases were obtained in the paraffin and styrene pretreated specimens compared to untreated samples. However, the increase rates in linseed oil pretreated specimens were generally lower than untreated specimens. Regarding water repellents the most successful results in all tested properties were determined in styrene pretreated specimens. The density, hardness and strength properties of all specimens increased with the increase in compression ratio. On the other hand, the increase in the compression temperature negatively affects the properties of untreated and linseed oil pretreated specimens, while having a generally positive effect on the properties of paraffin pretreated specimens. However, all tested properties of styrene pretreated specimens have increased significantly due to the increase in compression temperature. The increasing strength properties of wood as a result of densification have increased much more with paraffin and especially styrene pretreatment. These combinations can be considered as an important potential for applications that require more hardness and strength.

scholarly journals Utilization of Birch Bark as an Eco-Friendly Filler in Urea-Formaldehyde Adhesives for Plywood Manufacturing

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 511
Author(s):  
Roman Réh ◽  
Ľuboš Krišťák ◽  
Ján Sedliačik ◽  
Pavlo Bekhta ◽  
Monika Božiková ◽  
...  
Keyword(s):  
Bending Strength ◽  
Urea Formaldehyde ◽  
Formaldehyde Emission ◽  
Birch Bark ◽  
Gravimetric Analysis ◽  
European Standard ◽  
Scanning Calorimetry ◽  
Wood Processing ◽  
Fagus Sylvatica L ◽  
Positive Effect

The potential of using ground birch (Betula verrucosa Ehrh.) bark as an eco-friendly additive in urea-formaldehyde (UF) adhesives for plywood manufacturing was investigated in this work. Five-ply plywood panels were fabricated in the laboratory from beech (Fagus sylvatica L.) veneers bonded with UF adhesive formulations comprising three addition levels of birch bark (BB) as a filler (10%, 15%, and 20%). Two UF resin formulations filled with 10% and 20% wheat flour (WF) were used as reference samples. The mechanical properties (bending strength, modulus of elasticity and shear strength) of the laboratory-fabricated plywood panels, bonded with the addition of BB in the adhesive mixture, were evaluated and compared with the European standard requirements (EN 310 and EN 314-2). The mechanical strength of the plywood with the addition of BB in the adhesive mixture is acceptable and met the European standard requirements. Markedly, the positive effect of BB in the UF adhesive mixture on the reduction of formaldehyde emission from plywood panels was also confirmed. Initially, the most significant decrease in formaldehyde release (up to 14%) was measured for the plywood sample, produced with 15% BB. After four weeks, the decrease in formaldehyde was estimated up to 51% for the sample manufactured with 20% BB. The performed differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), and derivative thermogravimetry (DTG), also confirmed the findings of the study. As this research demonstrated, BB as a waste or by-product of wood processing industry, can be efficiently utilized as an environmentally friendly, inexpensive alternative to WF as a filler in UF adhesive formulations for plywood manufacturing.

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